In my opinion, I believe we do actually have at least one avenue of attempting to make the game an E-sport. The problem is, it isn't one that would be entirely appealing the the current competitive audience, myself included.
The way I see it, valve got somewhat peer pressured into finally adding comp to their game after the success of overwatch and the undeniable cries from the community, and the developers did in fact say they want to bridge the gap between casual and competitive, which is something we have viewed as an issue for a very long time.
The problem is, valve's implementation of 6v6 is one of no restrictions, and whilst not something the majority of existing competitive players will see as balanced or even fun, it is however intuitive to newer players aiming to play the game more seriously.
Valve openly said they wished to balance the game around competitive play and even began doing it when it came to items like the gru or the dds, however, valve did say that they would value the results found within the in game matchmaking.
We tried matchmaking, didn't like it, and stopped playing it. The numbers reached next to nothing, Valve has no reason in their minds to value the competitive side of the game anymore.
Now the only way I see valve ever realistically caring again about balancing and growing the competitive scene, is if we are able to migrate a large group of our competitive players into playing an unrestricted ruleset. This was something sideshow said multiple times. If we are able to have the majority of people abusing an unrestricted ruleset in a highly competitive environment, it becomes extremely clear which flaws cause reductions in enjoyability and fun for the players.
We know that valve does not look at etf2l or rgl matches as reasons to balance the game, instead I really believe that if the in game matchmaking was viewed as a beta as let's face it, it really does feel like one, and we were able to migrate a large portion of our community into playing this rule set as the main form of competitive play for an elongated period of time, and it isn't that far fetched for people to really enjoy it, I mean we have seen how faceit 12v12 can be fun simply because people play the objective because any incarnation of tf2 is still tf2 which at it's core is an extremely fun game.
so if we migrate, and really apply the majority of our scene the player numbers for that mode specifically will increase, you will see a meta establish and playstyles and strategies emerge. then you have two outcomes.
1. Valve notices increases in players making use of their rule set and become more willing to listen to feedback and advice, slowly eventually balancing the game into one that has a high amount of competitive substance and things end well and even if they don't, valve have said they would have invested into a lan tournament if the format was one they identify with which nr sixes is that so you could see if valve would be willing to invest into an i-series type event with their ruleset.
2. Valve doesn't care, we understand we have exhausted all the options available to us as individuals, and back into the underground roots we go continuing to play the game in a way we value, but at least we can say we actually tried everything.
At the end of the day I do feel the way we currently play the game is infinitely more fun than the competitive mode inside the game, but I do think trying to get more competition of unrestricted 6s was something we never really tried outside of some cups on rgl.