Most support Intel HDA.
The problem is that people don't use onboard audio anymore (because its incredibly and audibly noisy). They use USB or Bluetooth.
Bluetooth absolutely isn't standardized and is a mess, and USB miiiiiiight be okay if you limit to a subset of EHCI and USB Audio Class 1.0 devices.
At this point, its easier to just use Linux and run your game as pid 1.
Bluetooth sucks against the raw codec of a soundcard. If you want lossy music, that's it.
But given autotune trends and how genz-ers grew up with shitty early smartphone loudspeakers and not much better BT ones they aren't used to proper music and their tastes are rot forever.
You can strip down Linux significantly as well: no multi-user, no extra syscalls, no FS support beyond initramfs/tmpfs, etc.