The teens and pre-teens spend a great deal of time diving or figure skating, because they get occasional roles in the shows that need extras

I have one mom who does most of the childcare at the center, but other parents help too. And two "teens" ( actually adults, but I needed teens for my storyline before the update) who do whatever hobby is being asked for in the goals. One did ghost hunting for the Halloween quest, and the other is currently working at fishing.
I had a couple of pre-teens level up through ballet and karate to unlock the rewards ((wallpaper, trophies, etc) and two teens who did the teen idol quest.
I think it really depends why you play. I like to do storylines and decorate, but don't care about the monuments or town value.