Modern AMD GPUs work better on linux than nvidia. No tearing, multi-monitor works, and vulkan is very smooth. Nvidia is actually less stable, and has some peculiar quirks, such as needing composite manager running to get rid of tearing, spotty multi-monitor support, etc..
You are dismissing people saying they ARE having issues with AMD on Linux. In fact my AMD card does not do multi-monitor, and in this thread I'm not the only one that has multi-monitor issues on AMD.
Which card are you using? I'm aware the older cards are still bad. Especially if you still need fglrx. In my personal experience, the modern AMD GPUs on linux is first time graphics have worked reasonably well on linux. Even intel drivers are riddled with bugs and instability (not to mention they still don't even do gallium). GMA 3650 (powersgx based) being the most infamous worst driver ever.
A 5500 XT bought in June, so not old at all. I've heard the opposing argument, that since it's a relatively new card (out since Dec 2019?) I should expect some bugs, which is insane one year later. It's actually unusable, I have to log into my machine via SSH to restart it, or force reboot. It might break after 30 minutes or 3 days, when idle or busy.
AMD developers in that thread are chasing their tails and still haven't figured out why so many cards are having issues, and why other aren't, but as a consumer, that's really not inspiring at all.
Funny, I have 5600 XT (Sapphire Pulse) and it runs like dream. The out of box experience with Linux has been very good. Note that some of the aftermarket cards are actually bad and the instability might not be software related. Before 5600 XT, I used R9 290, and while it did require some tweaks to enable all features (due to being older card), it still ran relatively stable and in general was better experience than any nvidia card I had used in past.
