I haven't gotten this sense from the conversation at all.
The pushback your getting is from people that enjoy the Randomness of Random. You might roll high on your teammates, you might not. You might roll weird ships or non-meta divs, you might not.
Much of what's being said about "Well, if there are 4 Unicums, then distrbute them amongst both sides" is that it's self-defeating in the long run. If you have 4 players that are 55% Win Rate and you divy it out so everyone with above 50% Win Rate is facing another person who is the same... then the Win Rates fall to 50% over time. As that happens, Win Rate as a "skill" metric stops being valid, and a different form of identifier would be required.
This is a complex game that is more than just showing up and doing damage. Most of a person's "PR" is related to damage, so folks get a skewed impression of damage's relevance in the game. Support and setting up Teammates has an intangible benefit which shows instead in Win Rate, which would be negated through this weighted system
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As a bit of a call back...
I used to play shooters in the 90s. There was no Matchmaking. You just found a server with people on it from a list and you joined it, kinda like hopping into a random Training Room and just going along with whatever's happening there.
Sometimes you were the best on the server. Sometimes the worst. You had no control over what you would find, but you did have the ability to leave and try a different server.
No stats were tracked in the game, so the only thing that mattered was what you brought to the table when you joined something.
Not gonna lie, I love the fact that Random Battles is actually Random because -I miss those days-. Current SBMM means I'll play a game until I get to "100% Effort or you lose" which gets old after a while. Sometimes it's just nice to play the game at a casual level that isn't 100% tryhard to win/lose.
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As a metric for what SBMM is like, play Clan Battles. You rise until you reach your skill limit and face others that are similar. Clan Battles are TIRING. Folks play for a few hours and then need to rest for an extended period of time, because if yo're not giving it 100%, then you're just losing until you reach wheverever 90% is located... or 80%...