I can't say much for missing the q's, but like any other ladder as you progress higher it gets more difficult. Not only mechanically (landing skill shots/dodging skill shots) but game sense in general. Where to be/where you shouldn't be at any given time on the map. Planning the next moves before they happen, etc. I'm not a pro (bounce between d4-5), but there's a ton of aspects to this game other than having a good kda. You could go spectate games of all levels and find someone with a massive lead/carry potential but still lose. Could always watch some high level streams and see what some of those players are doing, and try to predict what they are going to do next and more importantly, why they are doing it.
-Corporal B