The Devs have responded to all these topics in the past, and I’ve summarized them at How Competitive Matchmaking and Rating Works (Season 20). People keep whining because they refuse to understand how the system works.
Quicky:
People playing much better than their correct rank move to their correct rank fairly quickly.
People intentionally throwing/boosting have to be dealt with with the banning system, not the ranking system.
Jeff didn’t say this. MMR is rank. SR is not used in matchmaking, but is just an easier to read version of MMR.
Open division is a thing. There are also various discord servers for unranked pugs.