It's not about work, it's about the result.
Yes, if teams were matched by some form of skill metric then teams would likely feel more evenly skilled. The downside is that you move to a point where matches are 50/50 and the only way to actually push through and win is to play hardcore. If you don't give it your all, you slide back and lose over and over.
In a competitive sense, that's great. Effort = Reward. In an enjoyable game sense, it means it's Tryhard or lose... which can get really frustrating long-term in that there's no ability to just... play.
Random will yield weird results sometimes, but on a whole it's just going to be a random smattering of whoever's on and hit the Battle button, so it gives a lot of replayability due to the completely unpredictable nature of what you'll face and see. Also, given the nature of the random, sometimes you're the best on the server and other times you're the worst... so it can make for highlight reels one game and a lot of learning the next.