I feel like Dominon shouldn't have been removed. It was literally the only unique game mode, where the towers and nexus weren't the objective of the game, it was just not as updated or balanced. Now TT is fun and different from SR, but the objectives were the same as SR, destroy the nexus. Even ARAM is the same, but not Dominion. If we wanna have something different from time to time, then we had dominion there to help with that.
I feel like with the way they are balancing ARAM and TFT, they can balance Dominon with no problems. If they do this, then they can attract more players and make it somewhat more enjoyable to play since we can still have something different to play.
There were even tournaments for dominion that people had, so it wasn't even that bad of a map.