Obligatory: I've worked on thousands of computers and servers and never worn an ESD strap and never had any issues, though when I've touched a couple $500k+ servers I've definitely considered if maybe I should.
Same, I think it's just one of those things that's persisted from "the old days". Like needing to close recent apps on your phone or needing to charge a new device "for at least 6 hours before using it" and it's really not as much of an issue with modern hardware.