I don't know if my body chemistry has changed with age or if I just shower more frequently and sweat less but when I was younger from teens to 20s my crotch would get a nice funk to it.
It was not dirty smelling but a nice subtle musk,Iv noticed I do not easily get like this anymore and I'm kinda disappointed. Recently reminded of it when I sucked off my straight best friend and his musk nearly made me cum.
Whenever I attempt to get the good musk its either far more subtitle or on the dirty side making it gross.

Likely related to a subtle drop off in testosterone levels. Get yours checked, that could be the cause.

Maybe you are just less active