Questioning Match Making

First, I would like to start by saying I have never raged when it comes to match making and who I get paired up with, but my recent experience with match making has gotten me so frustrated with Riot's match making system and questioning if my MMR really does matter. I am in Plat 4 atm and in a couple of my past games in ranked I have been paired with people that are the usually plat 5 or 4 but face people higher then my respective ranked. I'm not complaining about this, however very often the game is usually a total stomp with my team getting trolled by teemo mains or just straight up people raging for apparent reason . My worst game was when I played with a gold 1 Yasuo which is really weird for being a plat 4 rage for no reason and being unwilling to work with the team in order to win; and the in 2 of my 5 games I get paired with Teemos that usually get crushed and is unable to contribute to the team at all. Also, I am questioning the importance my MMR because I have a higher mmr than average but I am being paired with from high golds and low plat but face mid or high plat which confuses the crap out of me. Maybe it's just me and I'm sorry for making this a rant but the way ranked is right now it is painful for me to queue locking in Azir and having my teammates get slaughtered while I am slowly farming to try to carry this game. Hopefully, other summoners aren't getting unlucky like me but have fun to play league and have a good day.