You can run the bridges yourself, they're open source. Requires more work (and your own server, of course).
As for third party services, yeah they can block you but then you'll end up in exactly the same situation as when you say "I only use Signal" anyway. The whole reason people are setting up services like this is because the people they chat with aren't on their platforms if choice.
Having worked for a software company that needed translation services, I can confirm that translation software is indeed very necessary.
People would notice when the word "date" is interpreted as "date on a calendar" in one file and "romantic event" in another, but AI sure doesn't.
Even Google's apps have broken Dutch translations by reusing existing strings for different contexts that don't mean the same elsewhere. "Search" gets translated to different words depending on if it's used a noun or a verb, for fucks sake!
You can use tools like Stallwart and Mailcow qnd even Mail-in-a-box to make mail hosting a LOT easier. One does not simply configure ClamAV as a milter and chaining DKIM validation too late I the process is a great recipe for random spam status issues.
You just have to accept that nobody using Google's or Microsoft's email servers will receive your email in their inbox ever again. All of your outgoing email will be marked as spam, unless you slowly trickle non-spam emails at rates of dozens to hundreds a day to various email servers to build up IP + domain reputation. If you're not a marketing company, that will probably not happen. That includes almost every company, big or small, local or international, using their own domain names. Customer service will likely ignore you and email that doesn't get delivered will be considered your fault. Of course you can fight against the system by still using an independent email server (like I do) but know that you're a tiny drop in an ocean of The Big Three email servers.
Also, reserve four to eight hours a month for maintenance and dealing with problems. Easy to do as a student, challenging as a parent.
Futhermore, for your domain name, make sure to check the requirements. You may lose the rights to your domain when you emigrate, or when your country ceases to exist (unlikely) or leaves the economic union controlling the domain (like the British people with .eu domains). You may find the Taliban in control of your domain one day (because you chose the funny .af ccTLD). Also pick a TLD that's not full of spam already, like .biz or the ones that used to be free (.tk).
Local folders are traditionally meant for protocols like POP3, where the standard procedure for email is to get downloaded and deleted from the server. IMAP is designed to keep email on the server, like you'd expect in most cases.
You can copy mail to local folders as a backup, but the problem you encountered is that the protocol was technically right, but you didn't know about the details of migrating email providers. This problem should only happen in two scenarios: when your email vendor seriously fucks up, or when you migrate mail servers without first copying all the email over. As long as you keep backups for the first scenario, and remember to copy over email first during the next migration, you should be in the clear.
You can use your email in whatever method you prefer, of course. I prefer to keep email centralised around my server. If you're going local-first, you could consider using the older POP3 protocol instead, which is more local-oriented.
I quite regularly see installation stall on older and cheaper phones. One single app install is fine, but when five or ten apps update all at once the phone becomes sluggish for minutes.
With Android consisting mostly of what, four instruction sets, this problem should've been prevented years ago in my opinion. Precompile for the most common platforms, leave the current slow processes for instruction sets nobody uses in practice, like MIPS and RISC-V.
Tap on an app there. There are three settings. "disabled" for basically freezing apps once they're no longer in the foreground, "enabled“ for doing things like occasionally checking for content updates j the background and playing music while other apps are on the forefront, and "unlimited" for the setting you're thinking off, which badly designed apps often need to not be killed when they keep hitting the CPU in the background while the user hasn't interacted with them for ages.
Other manufacturers have even worse appp killers.
If you have your client configured for IMAP, Thunderbird will synchronise with the new server.
If you did not transfer your emails from your old server to your new server, that means the new state is "empty inbox" and synchronising means "removing everything that's available locally".
To fix this, either do a server-to-server transfer from the old email provider to the new one (there are tools to do that, like imapsync), or try importing emails from a backup into Thunderbird after synchronisation succeeds, so that Thunderbird will upload the messages. It's possible that you will need to use a tool to rewrite the message IDs so that Thunderbird treats the messages as new items.
If you have already cancelled your old server provider (so a server-to-server transfer is not possible), restoring from backups may be your only solution.
If you don't have any backups, your email may not be lost. The first thing you need to do is copy Thunderbird's data folder to a backup location, just in case Thunderbird tries to do maintenance on the file while you're performing recovery. Then, use a tool like Thunderbird Reset Status (I can't quickly find a more up to date tool but they probably exist) to unmark the emails in the Thunderbird mail store as deleted. Then set up backups for your new mail server.
If you use the trick above and Thunderbird starts deleting emails again, repeat the trick but break the email account settings first. Then, set up a second connection to your email account, drag over all the undeleted emails so they get uploaded to the new server.
Mastodon is just one of many applications that uses AP for their own custom purposes. MissKey and derived software has some kind of emoji response feature to posts that's basically unimplemented anywhere else. Lemmy's boosting trick to make comment sync make interoperability with timeline based social media a spamfest.
Maybe I should check again, but last time I looked into it there were no commonly used ActivityPub compliant servers. Everyone does their own thing just a little different to make the protocol work for their purposes. Even similar tools (see: MissKey/Mastodon, Lemmy/Kbin) took a while to actually interoperate.
As far as I can tell, the idea behind the original design, where servers are mostly content agnostic and clients decide on rendering content in specific ways, hasn't been executed by anyone; servers and clients have been mixed together for practical reasons and that's why we get these issues.
It's very useful in sealed devices (smart watches, ear phones). Much better than pogo pins on your skin; whatever metal they pick, someone is going to be allergic. Things like active pencils (Apple Pencil, but als the Windows open standard ones) also make a lot of sense to charge like that.
I also use a wireless charging stand for my phone. Most phone stands have an opening for a cable, but for some reason that opening is always at just the wrong space, or not right for the cable. K They're also useful when using your phone for navigation in your car. I find a cable sticking from the bottom of my phone quite a handful to manage, especially as the USB ports are all so close to my gear shifter.
For those still sporting lightning iPhones, it also provides a universal charging option.
Oh, and then there's the edge case of "I want to plug something into my phone and also charge it". Tiny flash drives, 3.5mm converters, you name it. Most phones only have one USB port, so using it for anything but charging usually means not being able to charge unless you go wireless.
Still, wired is the way to to moet of the times. Wireless is just a nice backup, and maybe a fun gimmick in certain furniture.
I have a lot of apps on my phone. Several government and banking apps require to be updated at least weekly or they're locked out for security reasons. Sure I could interrupt my 2FA login flow to update the app (assuming I have fast Internet available) but why bother? Google Play should be updating those things in the background while the phone charges. Same with F-Droid, though that's buggy and gets stuck all the time.
My Android devices are nothing compared to my Linux installs, anyway.