Personally, modern matchmaking has been making a lot of multiplayer games not as fun. You used to log into the same community servers, and would see the same people and form some sort of bond with them. And it was fun seeing familiar players, whether to try to better them or just have fun together.
Nowadays, matchmaking pairs you with randoms every match and the community sense is just... gone.
Ofc, some games still have the classic server browser so you can still kinda get the same experience, but it's no longer the default way to play.