So I've been playing since midway through season 2 and have played pretty regularly or in the cases of season 3 and 4 alot. This game has made some amazing changes and honestly some absolutely terrible ones. I know the current topic of discussion is "dynamic queue sucks" which to be honest with the amount of league I've played isn't even the biggest issue. Since season 6 has started I've lost all desire to play solo (except to get back to gold) and now pretty much only play with friends and its not because of dynamic queue its because of the gameplay changes. I'm going to just throw these out so If you disagree I don't care. I'll list these as they come to mind.
1. Keystone masteries and how they've destroyed any semblance of balance:
League has been a game that has struggled with balance but not as badly as this season, the keystone masteries have caused champion matchups to be completely irrelevant, as an example look at how long malphite was hands down the best toplaner. I can't even be bothered discussing how thunderlords is too strong.
2. Riots hand in controlling the meta:
Some might argue this is a good thing, and to be fair its not 100% bad, for example the marksman and mage updates were a nice way to mix things up.
The problem lies in that item design, champion nerf/buff/changes, I'm not an expert on this but even I can see that its not good for the game, there are now objectively terrible champions within the game that if you are not some godlike player will drag your team down, although this has been the case at points in leagues history its so much more emphasised now as the pool of champions worth picking reduces in size, competitive play now consists of who can pick what first and it just sucks. I used to love the LCS even fighting with my friends to get them to watch but now its boring and I blame this heavy handed meta.
3. Length of games and how hard it is to make comebacks:
I'm gonna lead off with what I believe to be the biggest issue league has, TIME. Death timers, surrender timers, objective timers. Everything is too long!
Right now the state league is in there is a heavy emphasis on snowballing, with stacking dragon buffs, long lasting rift herald and super expensive but super effective items, once a player gets ahead aslong as they don't intentionally throw or play incredibly stupid it is incredibly difficult to stop them. This is partially the reason why premades are such a problem in ranked, the camp your friend until they become a problem strategy is so effective and with added bonuses of increased communication, you don't need a 5 man team to get ahead in ranked you just need to get one person extremely ahead, because once someone is ahead it is so difficult to stop their snowball comebacks can be close to impossible.
4. What can make league easier to deal with and possibly enjoyable again that riot will not implement:
-Earlier surrender times and learning that 3 is more than 2 in a surrender vote ( having a stubborn or troll premade continually hit no in unwinnable scenarios)
-In both normals and ranked have a better matchmaking system (I'm gold just because I've played for 4 years doesn't mean I'm as good as diamond players)
-Introduce some means of a comeback (cheap items that arent strong enough to win games with but can pull you out of a whole) (to counter cheap items make expensive power items)
-Leave the meta to evolve (yes balance champs but don't make them objectively good or bad as you are now)
-Make some sort of change to the game that makes death timers less obnoxious, if your games naturally last long don't add artificial means of ending them if i invest a long time to a game I want the final moments to be tense yes but not so fleeting that one imperfection and a well laid out victory gets sweeped away. Nor do i want to play a game that if I die once the laning phase is over (top lane anyone).
I know this is absurdly long and maybe not all of it is all that useful but its my personal frustrations over an incredibly frustrating game that after so many years of playing I feel like I'm being pushed out of by the company who made it.