I don't actually understand why the competitive community is so set on keeping comp TF2 a stale, "perfectly balanced" game. Games aren't supposed to be perfectly balanced, that's just boring, unchanging and practically brainless from a strategy creation standpoint. Good balance comes from having a few overpowered aspects of the game, so that in a highly competitive environment, teams create new strategies over time to adapt to the many different things other teams are doing to take advantage of those overpowered aspects. There's also a case where something may make a class overpowered in one area, but that area encourages a different playstyle which is overall easier to deal with.
People right now are unfortunately delusional that TF2 is going to grow as an esport if we ban weapons and limit classes. It's not. TF2 also isn't going to grow as an esport if the devs balance the game exactly to your liking. Other competitive communities are able to accept new patches and adapt to them, and the games supported by those communities have some of the most popular esport scenes in the world. Our community has this detrimental mindset that we should distrust the developers and instead, as non-game developers, make big assumptions about if the game is perfect for us and our old strategies and then act on those assumptions through bans. This is the one thing holding us back and I hope people realize this and advance TF2 much further by getting rid of this ban system.