I am a mid-tier pvp player. I'm better than newbs, but I get crushed like a bug by the good players.
My problem with CBMM is that I feel like how I play has virtually nothing to do with whether or not my team wins a match.
I can play well and lose, I can play poorly and win. In both cases, the match was predominantly controlled by the best players, and the rest of us are just along for the ride.
I can imagine the responses - "try harder," "practice and get better," etc. That's all fine, whatever. I've been playing the game for 6 years. I personally think I'm close to the limits of my capability. I'm old, my coordination and reaction time can't compete with 14-24 year olds. But that's all distraction anyway.
My point is that I don't feel like I make a difference in crucible. I feel like my gameplay doesn't matter. Half the time - or more - it would be better for my team if I just hid the entire match, to not give points to the other team.
What if maybe 50% of my games were like today's games, dominated and controlled by the best players, but the other 50% could have players that I can compete with and make me feel like my gameplay matters. I would enjoy that. I would feel like my efforts rewarded.