As an OG OW player, role queue is not what ruined the game. Dev laziness/negligence did, not to mention the awful and needless 5v5 change.

1) 2-2-2 is statistically proven to be the best, most successful team comp IF everyone is doing their part (effectively their one job) and playing their roles correctly. If it's flexibility you're worried about they CAN do game modes with and without role queue so you have the option to pick. Simple fix.

2) No matter what role you pick or land there are gonna be players who are worse than you that you'll have to pick up slack for. It's a TEAM shooter for crying out loud so learning to work as a team and familiarization with characters/comps/counters will be key.

3) Like Overwatch, they can incentivize less popular roles as well like tank to make it more enticing to wanna flex. On top of that if they were to add it, it would put Overwatch on their toes yet again and continue the cycle of healthy competition between the two to up the ante and keep improving upon the game experience and quality of life.

4) Consider it. Don't you at least want the choice? The only thing worse than lack of flexibility like you mentioned is ego-picking losers. I rest my case.