MMR Suggestion
TL;DR: Base MMR on Perks, not how much you Win or Lose. Lock Loadouts/Characters when Queued.
So I've played this game for a long time. Back when it first came out to Xbox. Ever since MMR was introduced there has been a steady decline of wanting to play the game. Getting 8-10 games in a row of non-stop high tier perk games when I am not even running the best gens perks. Sometimes none at all. Even after taking months off from the game I still get stuck with people who use barely any other perks in the game except for the ones that can almost guarantee you a win.
My suggestion here is that your MMR is set by what type of perks you are wanting to use. Higher perks used more in popularity will result in you getting paired with people using perks of equal value. This way people who want to just use off meta/random perks will get paired with others who will do the same, or no perks at all. Granted it might take a bit more observation and having to track what perks are being used the most often, but BHVR has already shown that they keep track of that already.
Now I still say that you have a base MMR that you reach if you are new to the game, such as it is now. However, once you've played enough games and win more often then your MMR is set to a normal amount and your perks will be added to your base. This way new players won't be getting paired with veteran players. Or they shouldn't be at least.
I am not a game dev or a QA person, but I feel this could be a way to keep players interested in playing more often. If you want to try your hardest and get some competitive matches in, then set your loadout to those perks. If you'd rather mess around with random perks or do some meme shenanigans, then equip lower tier perks or none at all and go at it. I feel that if the MMR is set this way then you won't get paired as often with people who want to go tryhard all the time. Even if the competitive people decide to play with lowered perks or none, then it isn't guaranteed you'll run into them.
If it was to be this way, you'd have to lock loadouts before queuing into games. They already have this in a way with Killers, so Survivors would have to be the same. No switching loadouts or characters in the middle of a lobby. This way people can't queue for a "Casual" game and then swap last minute to their "Win" loadout. I'm not 100% sure if items or add-ons should count towards MMR, mainly due to the fact that some items gain benefits depending on the perks you have.
As I said I am not a game dev or QA person. Just trying to find a way to make the game more fair/enjoyable. This suggestion could help out with people wanting a Ranked/Casual mode. Just depends on how you want to play.