The web serial "Worm" (Parahumans) is an interesting take on this. Powers tend to show up around teens, but stay forever. A lot of hero teams have a "youth" team as well. They handle low stakes stuff, to get some practice in, while the adult teams take the bigger risks.
Do the oldest parahumans take the biggest risks? Because that would be ideal.
The job of old people is to clear the way for the young! It's how humanity is supposed to move forward.
I find it interesting that this is the opposite of how finance works: When you're young you're supposed to take the most risks while the old are supposed to play it safe.
Yes, the young parahumans (wards) work in big groups and deal with smaller crime. Usually a ward will never encounter or will be told to let someone else handle a really really powerful or brutal villain but sometimes they don't have a choice like in the case of sh9
There also another exception; when fighting endbringers ever hero and villain is allowed to fight