IMO people act like it’s training wheels so they can get better, but it’s more like turning the game to easy and not having to face any challenging hurdles. When people go into a game on easier difficulties and then try to play it on a higher difficulty, they actually generally have a harder time than if they just played the game on the harder difficulty to begin with (with some exceptions). Players should be getting better by experience not algorithmically making them feel better by pitting them against other poor players. It worked just fine for a long time before the invention of SBMM, and servers used to do a lot of the filtering for us before that stopped being common (for absolutely no good reasons).