You got that backwards
SBMM creates nothing but sweat lobbies every match if you are a decent player.
I'll give an example. Go play Apex again after not playing for awhile. The first two or three matches will be great, with a mix of good and bad players. But once the system detects you have like a 1 kdr or above then you're fucked. Every match after is sweaty. Happens in every game with SBMM nowadays.
What happened to social playlist just being a random mix of players. Now even social is filled with SBMM