The f do you even mean. Overwatch was a hugely popular, fun and successful game. Basically got the hero shooter genre off the ground by itself (and no, TF2 isn't a hero shooter). Their problem came later, with new heroes and balance changes that invalidated other heroes. If you loved playing the big dude with the shield, the addition of characters that can stun you and disable the shield through it made you stop playing. If you played the sniper, the removal of full charged bodyshots killing weaker, fast characters was the death of her and made you stop playing. Repeat for multiple other characters that were incredibly fun and got changed or impacted by new heroes, add in the ones that were broken from the start (i.e. angel chick invalidating an entire push using a single button) and the game will stop people playing.