They don’t really have to support the controller, though. Steam input lets you map controller inputs to kb/m inputs, so no degree of controller support is required. If there are any programmes that don’t work (which is possible, there are weird quirks in any system), I’ve certainly never encountered them.

But then for that you have distrobox, which is great. If that’s not enough, running another OS is also trivial, so that downside really is only ‘kinda’, as you say!