SSE4.2 specifically, POPCNT is part of that. It was introduced in 2008, while the previous requirement for Win 10, Win 8, and in Win 7 after a 2018 update has been SSE2 from 2000. So Windows 11 bumps the oldest hardware requirement from 18 years down to 16/17 years.

FWIW, Linux Mint 20 doesn’t have 32-bit builds so it isn’t compatible with processors that don’t support x86-64, and the first Intel processor to support that is from 2004.