Balancing Issues Regarding weaknesses

I know every champion in the game has a weakness, well, ALMOST(NOT SAYIN NAMES HERE). But I feel some of these weaknesses are really dumb. Ex of good weakness: Gnar's mini gnar form is squishy and he mostly just pokes to gain fury. Ex of bad weakness: Darius has no escape, but he can run long enough so he can heal that 36% missing health plus spirit visage which he has bought, then he triple dunks and bye bye. In other words, who cares if you have an escape, if you don't even need to escape? Gnar's weakness makes sense because he is a balanced champion, and darius is less so. Here are some more champs with good weaknesses: Zac, Maokai, Jhin, and there is more. Some champs with bad weaknesses: Skarner, Riven, Quinn, Darius, and more.