The thing is, you don't NEED to overly sexualize big boobs. You can have busty characters and they can be fun to watch and their large bouncy bosom is just an added bonus.
For a real life example consider Dolly Parton. Great singer, fun to watch on the screen, and she had a plush chest.
Of course, realistically speaking you can only go so big before they become gag boobs. And then you have to hand wave them or play them off as a joke so the normy audience won't get uncomfortable.