This is what I thought, but idk why the literature about this is never clear that it's ARM Linux only.

which literature? (that question posed, i had to sleuth around to disambiguate oft repeated misinformation before figuring this all out)

I don't have it in front of me, have just seen conflicting info on a lot on articles about virtualization on Mac.

Well wait, UTM's official website clearly says it does support x86 if you're ok with the emu performance hit. Is that wrong?

that checkbox i mentioned above lets you choose to use native Apple ARM via the hypervisor.framework, or use Qemu which lets you do the x86 emulation?

It does support x86 at higher performance costs.