I don’t think hero pools will achieve your goal and will just create another ban meta as a single, random ban for tanks will ultimately lead to Dive being the only consistently reliable composition since it is the only tank composition with a redundant character compared to deathball or bunker.
The game was not designed with bans in mind nor were the rosters made with enough depth in order to support the idea. If you had implemented hero pools with OW2, and presumably more tanks and supports, it might have been better received. But as the game is, I think it is both premature and just another feature that we didn’t ask for that is indcative of the devs trying to do more by actually doing less - ultimately a lazy approach that only reduces player agency in the end.