6v6 is definitely the place to start
From my perspective, valve probably wont support competitive until weapon bans are gone. Class limits and poor class representation are also kind of a hinderence. Both of these bring attention to poor balance on valves part. On a lesser note, its worthwhile for them to adjust the game mode or classes just to make stalemates less of an issue.
However its pretty much entirely on valve to fix these things in a way while still keeping competitive play fun, as well as not harming pubs, which i think is a worry for them (though considering a lot of banned items are infuriating in pubs as well means this shouldnt be too hard, but with MyM they pussyfooted around a lot of balance changes).
A more posititve perspective is that aside from game balance itself, most shit we need is in place. Comp TF2s production value is spectacular considering its size and reliance on the community. A lot of players have left, but a good portion of them are still in esports and very well may return if theyre given the chance to actually develop something out of it. So if valve is actually prepared to start supporting the scene then all we have to do is just roll with it. Its just taking too fucking long.