The value of map knowledge is not relevant to the discussion.
Even if you’re missing both your hands and can’t actually play the game, the system will attempt to find you someone who is equally incapable.
If you’re new and don’t know maps, you’ll eventually get put with people who also don’t know maps, or are so bad in something else that it evens out.
It’s not a matter of not being able to compete, it’s a matter of not having the willpower to continue playing after losing a few games or not having a desire to improve.
Same goes with any matchmaking system, including ones that have random maps.