I'm looking for an alternative Youtube front-end for Linux Desktop but FreeTube for example doesn't support resolutions higher than 1080p.
Is there an easy to use client, that supports 1440p and higher out-of-the-box?
I'm using Freetube, too. While it fails to play 2160p reliably, you can always use a button to send the video to an external player like MPV. And MPV works without any issues.
Using Tubular here, which supports up to 2160p! Assuming the creator uploads at that resolution, of course. It's a fork of NewPipe, so NewPipe would probably allow for 1440p and 2160p as well, as well as any other fork of NewPipe (such as NewPipe X).
Ah, understood. I'm unaware of any clients for Linux that would do what you're asking for. You could try using Anbox to run android apps and use the android solutions I've recommended in my last comment through that, but that's all I've got. Good luck!