Speaking of Chess, even tournaments have mostly been using the Glicko (and/or Glicko 2) system more often than not over elo.
Heck, CSGO uses Glicko 2 where it mostly bases it on how many more rounds you and your team have won over the enemy, and puts negligible boosts and penalties when adding player performance (like, in order to truly cushion your losses or pad your progression is to honestly play like a god, but even then the system doesn’t care).
Honestly, what I want to suggest for Overwatch is more of just players playing to win kind of thing. Remove PBSR all together, make players play to a point that they have more points over the enemy team, more time than the enemy team, basically a higher score over the enemy team more often than not, and make the system rate player performance based on teamwork via really grading it on how much better you did compared to the other team, that way we’d see less one-tricks that alot of people do to game the system, and probably make LFG more relevant and taken more seriously.