yeah just get an rx580 , i have it and it is perfect for fhd gaming

This looks like the usual case of distros shipping old versions of a lot of the things the graphics card needs, and user not knowing how to deal with it. It's not specific to AMD, you can run into this with any hardware that requires bleeding edge kernel + userland graphics stack + firmware.. and even with not-so-bleeding edge hardware if you try to use a "stable" distro like Debian or Ubuntu LTS from a year or two back. (For example I had the exact same issue trying a freshly released Thinkpad with Intel graphics on Debian stable.. graphics support was absolutely broken, and even after hours of installing and compiling and patching backports, it did not work. Installing a more up to date distro, or straight up the upstream software, helped)

I don't think it's entirely fair to blame AMD for that; it's not like they're the Linux distribution maintainer. They are playing along with the open source / free software ecosystem, which means there are dependencies that are out of their control, so to speak. It's not their job to do Canonical's and Red Hat's and Debian's (and every other distro's) job.. although I think they tried, and either they screwed up, or the user screwed up, or they both screwed up.

And that's exactly why open source people are very happy with AMD: instead of working against the grain and trying to ship a proprietary kit that works (begrudgingly, with some things, and not with others..), they play along. Mesa, Vulkan, the kernel itself, and everything else.. it's a large ecosystem and AMD is a tiny part of it. It just takes time for everyone to catch up, but once everyone does, you'll get support out of the box on any distro without having to deal with proprietary drivers on every install or kernel update.

I think it would be great if AMD could deliver these cards into developers' hands early enough, but apart from that, the burden of making everything tick relies on so much more than AMD. It's clear that they're having massive supply issues (and a rather tight schedule) with those cards so it doesn't surprise me much that they couldn't get enough of them out to all the relevant people.

The drivers work, if you know how to install the required software. The backported packages from AMD may or may not work. Proof: https://forum.level1techs.com/t/ubuntu-20-10-rx-6800-xt-how-to-steam-vulkan-up-and-runing-guide-wip/164137

In general, I still don't recommend people to go with Linux if they want hassle-free support for bleeding edge hardware on launch day. It goes far beyond AMD's hardware.