Easy thing to say when you're not the one donating your time for free.

I love what Valve is doing for Linux, but longer term, the onus is on them to solve the 32-bit compatibility layer issue (a-la Proton for win-to-linux, as well as their upcoming x86-to-ARM layer).

Expecting all distros (who again, are staffed mostly by volunteers) to do this work separately (i.e. duplicating all that work), for all time, is a big ask.

Don’t break userspace.

That's a kernel saying. A bit unfitting to repeat it for the distro that builds said userspace.

Isn’t the context of that quote around the kernel and kernel space vs user space? I don’t see how that thought really extends to distros that simply implement the kernel as one of their packages.

Userspace is allowed to break themselves