Like I said you're delusional. Averaging 5 kills a game isn't even remotely impressive and only having 1300 hours in the game you likely wouldn't even be on par with Diamond/Master level players. You might be having issues, but you are also no where near as good at the game as you think you are.
Also I'm going to assume you're basing your stats off of playing on the Switch, which isn't even comparable to to PC. Switch players are literally the bottom of the barrel in terms of skill.
Kills do matter in terms of determining skill, it's much harder to drop double digit kill games than winning.
Especially if your just playing pubs you should be focusing on frags and positioning since there's no penalty for losing.
Also as far as MM goes there is no way around getting matched up with players with higher elo than you. The pool of players is smaller and most solo queue pubs. So if the game only matched according to like elos, high elo players would be sitting in pub queues 20-30 minutes.
