> ... you can just assert that they’re all recent enough to at least have AVX2 that was introduced over 10 years ago, and have the program crash or misbehave if it ever runs on anything without AVX2

> However, if you are distributing the binaries for other people to run, that’s not really an option.

This all depends on what kind of software you're making. A lot of games set their requirements about 5 generations back, like FC 27 where the minimum is a Ryzen 1600. That lets them use AVX2 unconditionally and prevent complaints from users who tried to run it with a super old CPU.

Then you get whole Linux distros like CachyOS and Clear (RIP) that rebuild the world for each architecture level and have them as separate variants. I think it still counts as binaries for other people.