Low player count is a reason for matching the same players, even after Shaxx breaks up the teams. It is extremely annoying when it works against you, like Bex and yourself. But, it's also nice when it works in your favor, and you get to torture the enemy team.
Loose SBMM just turned a casual gamemode into constant sweatfest, makes trying to use anything outside the meta pointless. (Wanted to try some Touch of Malice gameplay for fun D1 vibes and constantly was up against Jade and Pulses.)