I think one of the thing that gets me about the game is that when you reach a certain point 90% of the characters you can get from a gatcha are completely and totally useless.
If you don't really care about dokkanfest bosses that much that number rises significantly
Ya - I think that's why they're trying to remedy it with Dokkans for older characters.
My first account had no URs until I hit rank 130. And I only ever got two. I grinded every strike character to have max super attack. My current account started with Broly and now I never get more than one of a strike character (mecha frieza being the only exception so far and soon fat Gotenks for nuking). When I can set up a team that allows one character to Super Attack as soon as he's out and proceed to destroy every enemy in nearly all story missions in one swoop, there's no real point in the other characters outside of beating Dokkan bosses.
Hopefully they get smart, add Dokkans to older characters and release content like that Japanese event where the stages have restrictions (i.e. only all STR, only villains, cost restrictions, etc.)