To be fair, BG3 just runs like crap. I'm playing it mostly on a decent PC, there were some dips in act 1 and 2, but act 3 has a lot more dips.
Still a great game, and the city maps in act 3 are pretty packed, but the frametime consistency is pretty poor.
And Vulkan was even worse, slighly lower avg FPS, same inconsistency and graphic glitches (random flickering black or white squares).
I see the "verified" badge more as a "no need to fiddle to get the game running" not a "you get locked 30fps with decent graphics" guarantee.
Always subjective what "runs well", someone might be accustomed to 4k@144hz while someone else is used to "cinematic" 30fps.
Both will notice the unstable 30fps, but the latter wont mind, just like most players didn't mind with Zelda TotK.
I think the main difficulty with Linux desktops is this "all or nothing" approach to the OS.
Recently got a Steam Deck and most of the games really just work, but that's a handheld where I play solo. On desktop I mostly play online with friends.
I really don't want to constantly switch OS depending on the anticheat situation when we play something else.
And then there is software (fusion360, simhub) & hardware (3d mouse, joysticks, ffb wheel, maybe VR?) that just works on Windows.
So instead of maintaining Windows & Linux on dualboot I just stick with Windows on the desktop.
And I used Linux for a long time on my laptop (and can't wait to ditch MacOS), still use it on servers, but the desktop is just a whole different beast.