let's take 
as examples they feel you can do so much with them even with an average skillcap and their kits are a bit overtuned
meanwhile there are champs who have positive winrates but feel like shit to play 
working as intended.
They have low winrates because of high skill floors, while you happen to play against people who have gotten above that floor. Most likely reason.
They feel more broken because you don't play against them often.
It's because if you aren't good with those champions, they are completely useless and just a 300g minion for the enemy team, whereas, to use your examples: Ahri can still charm and set up for a pick, Kayle can still ult and allow a carry to 1v9.
They are harder to play .. yasuo is an icon of feeding and ryze is very difficcult to play with even of this new rework ... so the first 20 game with them u will have less than 30% wr .. but when yu matser them .. yeah they are completly broken ..
