Canadian, sysadmin, trans rights are human rights, puncha-the-nazis, cats are pretty great, GNU Terry Pratchett.
Sure, if you a) keep mammals around and b) drink their milk. I’m not convinced domesticated animals have been a thing for all that long, evolutionarily. Long enough for some groups to have adapted, sure. We have adaptations for cooked food, too.
[Searches] Cattle probably around 10k years ago.
I would guess that humans have been around for what, 250k years? And that the vast majority of that didn’t involve a whole lot of milk after age 4.
So it wouldn’t have been to much advantage to be able to metabolize lactose.
That sounds like something a bat would say.