Look i get it it’s just that i don’t agree with you. I understand that everyone have the right to play their most loved hero, but this is exactly why they can do many things to improve and maybe avoid this in addition with the system. In Paladins for example, you can only select the hero when its your turn to select so it works basically:
- Team to pick first is randomly selected
- Team leader can choose a hero to ban and then pick his/her and before the match start can swap with someone else
- Enemy team picks
- Your team picks
The first ones to pick are the ones to select which heroes they’d like to ban (1 per team). You could ask the person on your team that picks first to save X hero for you and then swap with her or something like that. This system is necessary because devs can’t balance the game properly in its current state and the game is frustrating more people than making them have fun.
2-2-2 sounds like it will cause more issues than it solves. You’re in a match where one DPS is a one-trick Genji and is getting heavily countered, effectively making the game 5v6. No one else can switch to a 3rd DPS to offset Genji’s already paltry damage, now you’re reliant on the other DPS to carry the damage and not also be countered by the enemy team comp.
You’re in a match where neither DPS are good with hitscan/sniper/CQC or whatever the situation calls for. Well, too bad, no one can switch roles. Guess you’ll just have to make do.
You’re in a match where your DPS is just not doing it. McCree player that can only flashbang kill and a kid that’s middling at best with Hanzo. No one is able to get past an Orisa shield and you can’t even get to the first point. Guess it’s just a shoulder shrug kinda loss. 
The scenarios are endless. The game is meant to be played as an adaptive team game where players excel by being flexible between heroes and roles. The prevalent issues of people throwing and one-tricking will only be made worse by a forced 2-2-2.
With that being said,
I think the reasonable course would be to try to balance heroes better while also implementing changes that promote teamwork and communication. The endorsement system was a nice touch, as was the changes to the report system. But something little they could do would be to add a persistent background team chat, so you hear your team talking, whether you’re in team chat, group chat, party chat, etc… The team chat would be a lower volume perhaps if you’re not in team chat, and you can always mute toxic players, but it’s a team game where communication is important - it should be mandatory to at least hear your teammates who are trying to give call-outs and direction. Too often you only have one or two other teammates in team chat, and typically even fewer with a mic.
Edit to add: Hero banning is an awful idea. I hate playing with one-trick Genji/Hanzo/Widow players who aren’t in chat and refuse to switch despite not working well in the composition, but banning a hero isn’t the solution.
The development team has stated before that they will never force team chat on anyone. I myself encourage players to at least try to enter team voice chat and if they have a microphone to use it. That being said every player does have a right to turn off team chat, and I also will observe that most players do not use team chat effectively such as blaming others instead of making key call outs such as when an enemy opponent is very close to dying.
Changes have to force behavioral changes If we ever hope to improve competitive play. This is why role lock and 222 will be far more effective than what you may think. Yes your scenario is possible but everyone on the team is always making mistakes.
I guess that’s my point. It’s such an adaptive, fluid game and that’s why people love it. Every hero feels unique and they are constantly being tweaked and re-balanced. No one is perfect, and it’s nice to be able to think of how you and your team can change to switch the tide of the fight. My worry is that it will box the game into something that doesn’t allow that freedom to nearly the same extent, while still allowing people to throw and/or one-trick as an ineffective DPS and the rest of the team will be handicapped in adapting to that. When I have a situation like that and team is in chat, typically we work together and go 3-2-1 (as the thrower/one-trick is almost always a DPS hero) to compensate.
I’ll be interested to see how things pan out, but I agree changes are needed.