CSGO is a fantastic example where someone with poor aiming skills but good gamesense (holding angles, using echo-location where you move your view to triangulate opponents based on how the sound moves and what type of footstep sounds are generated, timings, grenade throws, etc) can wreck opponents with poor gamesense and better aiming skills.
I have gotten reported for walling but people just need to realize how much damn noise they make.
The Shift key became infinitely more useful once my ears acclimated to the setup change.
In many ways it's not so different than billiards/snooker/pool. Being a good shot-maker helps but just about all the consistently performing pros focus first and foremost on position-play and thinking several shots ahead.
I'd say in most of my games I've got more playtime, trying various strategies, and learning from mistakes, than the other 9 people in the game put together. But at some point it all just comes down to who wins a trade, and I very rarely win them. Game's still fun though, somehow.
Always amusing when this happens.
I've noticed people who perform best are the ones who pick a strategy and stick with it rather than trying to get the glory.
Another thing is lower level players use nades poorly and are always caught off guard.