That’s because when a player joins a match-in-progress, the teams aren’t reshuffled, and the player joining after the shuffle at the beginning of the match/at the end of the previous match is not subject to any checks or balances.
This is all just an inherent flaw of having A: no matchmaking whatsoever and B: a small playerbase.
They COULD try to put some kind of algorithm in Quickjoin to help create more balanced matches by looking at the match history of any particular player and choosing a server for them based on how they compare to other players in whatever servers have open slots, but the fact that 70% of players use the server browser throws a huge wrench into the gears. But they can’t solve that problem by removing the server browser, because then there would be no way for people to play on the same server as their friends without getting lucky, or creating an entirely new party system. I wouldn’t like that anyway, as parties tend to communicate or at least have some level of familiarity with each others playstyles or have past experience in teamplay, which gives them an unfair advantage over anyone they play against that isn’t in an equally sized or larger party, and dirty bomb just doesn’t have the playerbase to sustain a system where parties only play against other parties. That was my biggest complaint with CMM for the brief period that we had it. Getting put against the same fucking 6 stack multiple matches in a row and getting shitstomped every single time, because you’re solo queueing it and they’re working together like a well-oiled machine, setting up crossfires and organizing team composition and what have you.
Honestly the best thing they could do for the health of the game, even if it would make some players unhappy, is reinstating casual matchmaking, but without the party system. The whole thing would become much more effective and a lot easier to manage if it was restricted to solo-queues playing against solo queues. People can party up in faceit matches, but i think casual should shield players from the incredibly unfair odds that occur when a group of similarly skilled friends play together.
The only other notable change i’d like to see in casual matchmaking is a “rematch” button for when you have a good, fun, balanced match against another team, and would like to play them again, instead of being kicked back to the lobby to search for a new match. it could be a vote and require like, 8-10 votes to pass, effectively a majority across the whole server assuming 6v6 matches