I can assure you that Gold-Platinum is so much worse than Bronze and Silver.Because in Gold/Plat,although players should know the basics of a team game they tend to to die 7 times in 10 minutes and then give up and grief.
The matchmaking also doesn't make sense.In every game there is that one guy that afk farms and refuses to group and try to win and usually denies his team any chances to win.
Every game is a complete stomp.Honestly,i do not remember when i last played a balanced game when both teams tried their best and had a fun game.Honestly i do not remember when was the last game in which noone gave 5 kills in 8 minutes of the game.For those guys often you lose MMR and get punished because a certain player decided that.
In my last game i lost as a top lane Jax with 22 kills.I was so fed that i could 1 vs 3.However,our Vayne decided that it would be a nice strategy to afk farm for 39 minutes at bot SOLO,ignore his team's pings and refuse to help his team to try and win.
In another game, our jungle WW was 0/3/0 at the first 20 minutes of the game when enemy's Sejuanii was 1/0/8.WW never ganked and was dying into enemy's jungle since level 2,making the laning phase a hell for everyone.
Sure i played also poorly in some games,but i at least know how to group when it's appropriate.
I can't express how disappointed i am when i get 0 rewards for having a nice performance.You get only poor teams in promos or afks destroyning games.
I climbed to Gold 1 and lost 3 games in which i had afk players and got demoted again.