Recent testing revealed that Arch Linux, Pop!_OS, and even Nobara Linux, which is maintained by a single developer, all outstripped Windows for the performance crown on Windows-native games. The testing was run at the high-end of quality settings, and Valve's Proton was used to run Windows games on ...
It's more complicated than that, for instance i use software that processes telemetry data from my racing simulators that control my tactile transducers. there's a million situations just like that if you do anything more than basic games on a basic screen.
What about surround for triple monitors? There's just so many little things that become a pain in the ass the moment you switch to Linux when it comes to gaming outside of the most basic, straight forward instances.
You are right, many oddly specific gaming things like this are not that well supported, but the strength of Linux and open source is that everyone has the power to change it. The software that people have already developed to interface with proprietary hardware is great, I have a Corsair mouse and thought I would never have support for macros on it on Linux, but someone has already developed software that does a way better job than corsairs official software. It can do all of the same operations and doesn't hang or crash regularly. I'm sure a few of your issues have already been solved by someone. The brilliant thing is, Linux ultimately allows much more control over the software and hardware it is interfaced to. So something like the transducers you mention would probably be easier to do than it is on windows, but someone has to actually do it. Maybe the sim-racing community is just waiting for you to come along? ;)
I'm not vendor locked, and it doesn't suck, the team that makes that software are great guys doing awesome work and deserve the money they get
idk what you mean by plug n play regarding the triples. i don't know if you've ever had a triple setup, but it requires software to treat them as a single display and adjust for angles etc for a proper 48:9 fov