The two major mistakes this season: Dynamic Queue and Keystone Masteries

Dynamic queue has reduced the quality of games in high elo through the autofill feature, to be fair it has gotten better as the season has progressed, but the match quality was significantly better with the old solo queue system in the previous seasons. I've even noticed in my elo (Gold 1) match quality has gotten really bad, some games I'll be playing with platinum 4 and 5 players like a should, then the next game I'm matched with Silver 1 and 2 players. It's an absolute toss up of what I'm going to get every game, its inconsistent and the match quality suffers because of it. Queue times have increased for me, even in gold/platinum elo and while I've seen less trolls overall, I've seen more and more people who have been boosted through gold a la dynamic queue to get to "platinum" in my games. Since they've been carried all the way to gold 2, they think they can solo up to plat 5 ezpz, but in reality they still suck and deserve to be in silver/low gold.

Keystones have been a HUGE balance nightmare this season. Starting with "League of Thunderlords" giving unnecessary burst to already bursty champions, making them unbearable to lane against and fight at any moment of the game ( just to name a few. Then we had the Grasp of the Undying + sunfire, IBG meta which was an absolute nightmare. Free sustain that ended up being completely abused by champions like who are already balance nightmares on their own because of the nature of their kit. We have Fervor of Battle which gives ADC's so much free damage, and lets not talk about the new Ekko triforce build, which abuses this mastery as well. Yasuo can abuse this mastery by building one or two damage items, then full tank and still has relevant damage late game.

I hope that Riot addresses these major pain points come pre-season 7. I don't want to see players a full tier below me matched in my games and I don't want to see these "tank assassins" abusing keystones to forgo their intended "weaknesses". Yasuo, Ekko and in some cases Fizz should have tradeoffs for building one or two damage items and then tank. It's absurd that Riot has been radio silent on these issues for most of the season, even though they're the biggest issues affecting the game right now.