I didn’t say that SR and MMR are totally unrelated. I said that SR is not used in matchmaking. If you want to understand this, you really need to try harder to read what is written.
I don’t know exactly how performance based SR adjustment works, since Blizzard hasn’t said and my attempts to reverse engineer it have not been successful. One possible answer, though, is that both SR and MMR get performance modifiers independently, but if SR gets too far away from MMR, SR gets pushed in the direction of MMR (this second part has been verified, for decay and the match leaving penalty).
I give my arguments on which statements on SR vs MMR are more technically correct in the original post, so I will not repeat them here.
If Jeff’s statements are to be ignored, then the conversation is over. Without Jeff’s statements, proving the actual existence of MMR would be difficult (and practically impossible after decay is removed from the game next patch).
The streaks and stomps are are fully consistent with a non-rigged system, with only one match-making-rating, and I have done substantial analysis.
Overwatch Forums and https://www.reddit.com/r/OverwatchUniversity/comments/aatezy/why_match_quality_is_frequently_poor/
Note, however, that role queue should reduce streak length, SR swing, and stomp frequency.