Why Does MMR Exist?
WARNING: Unpopular opinion, but please read my whole post before you downvote.
The whole time I have played LoL since I hit 30, I always thought the MMR system was trash. You get punished for your previous season's mistakes and your rank is usually just determined by MMR.
Example: I have a friend who went 1-9 and got Gold 5, and one of my friends went 6-4 and got Bronze 4.
Why isn't your rank determined by how well you play (your grade rating) and how many wins-losses you got in placements, rather than this invisible number we can't even officially check?
Also, the whole LP gain system is BS. Why is it based off of MMR when it should be based off of your grade rating that game? It should also be based off of your rank compared to the enemies. For example, if you're Silver 3 and get matched against a team of mostly Bronze 1 players, you should get lower LP for that game.