Who wants to join?
This whole post comes from my experience joining and trying to use Peertube. The immediately obvious problem is getting creators to post on Peertube which is an entirely separate issue. Even once I did decide I wanted to join Peertube and try to find all the content I could, I still ran into issues and it just wasn't a smooth experience at all. I'm fine with that as I understand the fediverse works differently and Peertube is a relatively small project (especially compared to YouTube) and I can accept that because I support what Peertube is doing as an open source federated platform. However, most people don't care about all that and even if they hear about Peertube and creators start moving there, regular people will still struggle to use it in its current state.
"Default" instance
Creating an account is confusing and the whole "choose your instance" is extremely unintuitive for new fediverse users. Obviously this isn't unique to Peertube, but other fediverse platforms like Lemmy and mastodon have solved this by having a "default" general instance to direct people to (e.g. lemmy.world & mastodon.social).
Search/Discovery
This somewhat goes hand-in-hand with the previous point, but it's really hard to search and find new creators/videos. Part of the reason is searching in most instances will on search that instance and maybe a few other instances that are specifically federated with yours. The closest to a "universal" instance I've found is peertube.wtf, but it is extremely slow for me and sometimes just doesn't load at all. Maybe this has to do with the fact that it is also searching so many federated instances, or maybe it's because it's based in Denmark and I'm in the US. Either way, I created an account but it was basically unusable so I switched to TILvids which seems to have a decent amount of creators but isn't federated with many other instances. There's also Sepia Search but it honestly doesn't seem to perform great and it's very unintuitive to have to go to a different website to search, then the finding a creator/video but it goes to that instance, so to subscribe, comment, like, etc. you need to find a way to open that video within your instance.
I think part of the problem is that you are doing what a lot of people naturally, but mistakenly, do. Compare it to YouTube.
PeerTube isn't trying to be YouTube. The only thing they have in common, is showing videos. That's it.
YouTube is a commercialized and corporate owned video aggregator that takes their users, changes them into commodities, and then monetizes the content from it's creators who are forced to follow the dictates of an algorithm if they wish to get a fraction of the value that they've put in.
PeerTube is a decentralized and federated video aggregator that is owned by the people. The users remain users and there is no monetization or algorithm which forces a user to follow. Any monetary compensation is strictly between the user and their audience.
The problem you're talking about isn't a problem with PeerTube, it's a problem with norms set by corporate entities. People hate to learn new ways of doing things. PeerTube isn't that hard to use once you understand the basics and how it integrates into the Fediverse. There's a reason that most PeerTube instances don't accept registrations from people who aren't creating videos. Aside from cutting down on spam and bad actors, there's really no need for it. Want to find a video? Do a Mastodon (or other Fedi service) search for the appropriate title or hashtag. Then you can follow the creator and get notifications. You can even comment and like and boost.
In other words, no one needs a PeerTube account unless they are making videos.
But that isn't the norm. YouTube is the norm and people mistakenly expect a YouTube like service. So when they see that things are different, their brain short circuits.
But unlike a lot of people, I don't see this as a problem. I think it's a feature.
The fact that it forces people to learn a new non corporate lead way of doing things opens up a world of benefits that non Fedi people can't even imagine. Choice? Control? They have no real understanding of what those things really are. And because they aren't willing to learn something new, they get upset and don't bother trying. Which is fine with me. Because it means every instance is filled with people who were willing to break out of the mold and learn something new. THAT'S a feature.
So yes, while PeerTube isn't perfect and still has bugs to work out, it's fairly good at what it's supposed to do. Which is to serve videos to the Fedi and not just PeerTube. Anything else you want it to do or be, is based on your own biases that you most likely picked up from corporate owned services.
A noob question from someone who only has an account on a Lemmy instance: I check Mastodon most days and PeerTube occasionally. Federation is great in theory, but in practice it doesn't work between all kinds of applications. Are there Lemmy instances where an account actually makes it possible to follow or comment on Mastodon or PeerTube? If so is it widely implemented? I think I read something on my Feddit instance that hinted at that it might be made possible to federate from there to Mastodon some day in the future. The other direction probably works to some extent, but I haven't really had any interest in signing up for Mastodon as I'm not planning to micro blog myself.
I can subscribe to PeerTube channels through third party apps of course, but not comment.