I don't know if the "power, boot, pull power, repeat" trick works when it's in that state but you seem to have nothing to lose except a little more time at this point. 3-8 times usually will bring up a recovery screen if it works.

AFA this:

If the device is only good for two years, I'm hesitant to get another one, especially after reading as many posts as I have about people facing similar issues and just getting it replaced.

I'm only one data source but of the 10 modern Atvs I have personally (4th gen and up, going all the way back to the dev mule Apple sold for $1) and the 200 I manage as part of the day job, exactly ZERO have encountered this issue. I'm not claiming it doesn't exist or doesn't happen at all, just giving a counter-point that you don't hear about the ones that just keep swimming.

Yes. Absolutely.

I’m having the same issue. Everything other app is showing in 4K as intended.

You could use the built in tv remote in iOS. In order to do that go to Setting > Control Centre > Apple TV Remote. As soon as you’ve enabled it just connect to your tv and reset the device as usual.