As you get 50+ Five star heroes are you more or less likely to grind dungeons?
There are two ways to look at it:
(1) Your roster of five stars is so big you are more likely to get a dupe than a new champ, so it's even less rewarding if your 1/10 chance for the god tier you are missing goes as is statistically likely.
(2) You have a big roster so its easier to do dungeons, and a 1/10 chance at the hero you want is still too good to pass up.