Android

tldr: Motorola edge 60 pro

I was in your same situation, was running on OnePlus6T up until literally last month.

My previous phones were the Nexus 5 and the 6T, I tend to keep devices for a long ass time so I always seek phones with the cleanest stock ROM, mobile phones are quite disappointing these days it is either stupidly expensive flagship phones, or cheap phones with a shit load of bloatware or shitty ROMs. Rooting is out of consideration because bank apps and wallet, wallet does work with the right magisk modules but breaks my bank apps and vice versa the modules right for my bank apps won't make the wallet work.

On top I try to keep a budget constraint of not more than 500ish which took immediately Galaxy and Pixels out of the consideration. Also the latest Nothing phone (which was my considered option) they ask for a high price for what they actually offer. Last requirement, fast charge and twin battery which is mostly the reason why my 6T lasted for such long time.

So I settled for the Motorola edge 60 pro.

Pros: has everything I need, high capacity battery and limited AI bloatware which can be disabled, but aside that the stock ROM is a clean Android.

Cons: the curved screen, there's no glass protector which fits it and it's quite exposed for eventual falls, which I partly solved with a cover that flushes with the screen. Disabling the AI also makes the 4th button out of use which I would've liked to remap to some other function (or use it as a power button). Last but less important, not a Snapdragon.

Also they reduced the price recently because they're going to release a new phone shortly, which means probably you can get away with a pretty more than decent phone with around €400.

Some last words: if you feel you want to wait a bit more there's the Jaguar ROM around for OnePlus phones that is based on the Oxygen OS and bootloader can be locked after flashing so the OS thinks it is genuine. The battery consumption is more than solid compared to lineageos so it might extend your phone life for some extra months

Redmagic 11 Pro

If you don't care about privacy, and are okay with an okay front facing camera to get a ubderscreen front cam. Redmagic 11 Pro is a fantastic phone at a fantastic price. Remember though, in terms of privacy it's like buying xiaomi or Huawei device.

Personally, if I can't recommend anything specific, I just recommend nord series to anyone. I've also used it myself and the few people that bought it were quite happy.

Do note that it's a mid-range phone, there are definitely better phones, but for the price they're pretty much perfect

The Oneplus 15 is super solid this year as long as you can forgive the subpar camera.

iPhone side, obviously don’t get an air, and just get a pro.

It’s very possible that the new Samsung S phone doesn’t come out until late first quarter next year.

Avoid the pixel because the Tensor G5 is literally half as powerful as the other flagship processors. You won’t feel the pain of how slow it is right away, but a few years from now it’ll be awful.

Get a Pixel and install GrapheneOS on it. It is super easy these days, you can do it using just a Chromium based web browser. And don't worry there is no chance you will brick your device.

Gsmarena > phone finder.

Fairphone

Get a used Pixel for $120

Fairphone is a good recommendation, alongside being repairable and sustainable. If its not present in your region. Look into high end Motorola phones (low-end have bloat).

IMO, Best would be a oneplus. You can remove any ads and bloatware with Shizuku, Canta. It will be familiar, reliable, and last a long time. Considering, your usage habits.

(i've seen the horrors of redmi software and want to stay as far away from That as possible).

Yeah, they start to lag within a year of use. All the redmi phones I have checked have lag issues. If you must buy a xiaomi skip the redmi. Don't know about poco. But, anything not Mi should be avoided. Xiaomi charges a premium for its Mi series for a reason.

If your phone isn't slow, fix it. If its unfixable, or you just want something newer, get a pixel phone.

First try to fix your phone instead of buying you can easily replace the battery if that's not desirable then get a pixel 9 series phone (if you want pixel 10 then you have to wait for GrapheneOS support for it comes along) and install GrapheneOS on it (don't be intimidated it's a super easy and straightforward process)

i would replace the battery and put lineageos on it.
the new devices dont give that much performance and the prices on those are not worth it.

I don't use the computer part of a phone so I just bought a ZTE for 85 bucks.

Maybe try installing LineageOS on it.

Go with a pixel, yes Google is evil and all that but its the least bloatware system.