The paper goes on to confirm what has, to me, always been the most obvious reason to have SBMM: random matchmaking primarily benefits really good players, and disproportionately sucks for average-skilled players.

Yeah exactly. I avoid pvp like the plague these days.

Somewhere there is a fascinating talk that breaks down how modern matchmaking is designed to manipulate the players’ experience - give them less skilled players they can destroy which feels good, make a little boring stretch which will create a hunger for something to happen which can then be filled by microtransactions, and so on. Some company (Blizzard?) actually has a patent on it.