Grooming rules that might be a bit outdated

I was chatting with a friend the other day about how some grooming “rules” seem to have stuck around forever, even when they don’t really fit modern life. It got me thinking what’s one style or grooming rule you think is past its prime? For example, I’ve always wondered if the idea that men shouldn’t have long hair in a professional setting is still as rigid as it once was. In my line of work, compliance, things are pretty formal, but even there I see more personal expression creeping in. What’s a rule you’d be happy to see retired, whether it’s about beards, skincare, or something else entirely?