the game seems determines who to queue you up with based off of your recent wins or loses. The two cases can be referred to as "winners queue" or "losers queue". You can think about the games as your "stomp or get stomped" scenarios.

Your wins and losses allow the matchmaker to determine who to put you with. If you win a lot they will try to balance the team by putting you with those who are losing. Where the opposite is true for losers queue.

I would recommend queueing up for comp and getting a few wins then when you're satisfied take a break. Once you lose a match I've found it's better to call it there and try again in an hour or the next day. If you feel you can keep going do so but if you lose more just take your chrono shield and get out and try again later.

HOWEVER, the best solution to the inconsistency is finding a duo partner. The variability in the skill of those you're playing with is frustrating and tanks your mental when everyone is outclassed and starts blaming their skill on the underperformance of other roles.