There is a very simple yet very hard to implement solution. Changing the mindset of the ranked playing try-hards, by removing the forfeit vote and increasing leaver penalties, to account suspensions. It has become all too common practice to simply speculate a lost game and give up to 'save time' and get into a new fresh one and try again. This is something that has very much bothered me with MOBA's as they have become e-sports...Sports in general have a time limit to achieve points/progression, when the time is up, the one with the most points wins, if there is a tie, if there is a tie, and there can be only a singular winner, overtime is a thing/sudden death.
This has led to the vast majority of players that participate in MOBA's to not actually know what loss actually is, and become lazy and obsessed with a ranking system, instead of actually getting better and turning their lemons into lemonade. I would be more likely to watch MOBA e-sports if they did not give up, after getting destroyed a couple times in a team fight. These self imposed metas by the first players of League have become standard, and stagnant. Riot can balance all they want, but without the player base deciding for themselves to not just mimic, but create their own play styles, and do away with these ancient self imposed metas, they will never get any better, and the same 'pro teams' will continue to win time after time.