@BennSauna you're right on all 4 points.
1st point - you won't get much support for that pov around here. Although I understand it. Lots of players here still defend mixed input lobbies, I don't. It's just piling on to the rest of the existing issues.
3rd point - this is my main issue with sbmm, it gets to decide outcomes by forcing lobbies onto players regardless of their improvement. In it's view we all should have equal outcomes. Some would argue 3kd is very high and you should lower your expectations, but I disagree. Killing 3 players in a random lobby hardly seems like it should be unreasonable.
