I stand by the point i made years ago about runes and masteries

Originally the set ups you'd see on the old runes and masteries had people starting with incredibly similar set ups between the games archetypes for characters, supports tanks and dps classes. The bonuses given by these trees were incredibly passive increasing defense and offense marginally and giving those who wanted it the option of delving into a more quirky utility bonus. https://i.ytimg.com/vi/EjTifg2Oj5k/maxresdefault.jpg

The system had some throw away choices namely those in the utility tree however this was alright since just about every champion could either use bonus defense or bonus damage to give them a tiny edge so it wasn't problematic. As the system began to change riot has choose to put more emphasis on the importance of mastery choice which as i recall commenting before on the boards, put a strain on champs who couldn't use the new keystones to their maximum potential. https://i.imgur.com/H8M6TFw.png

These new keystones were more impactful sure but denying that they could be problematic would be lying namely Courage of the colossus , Warlords, Windspeakers, and thunderlord which all had periods where they more or less defined the meta and if your champion didnt them at the time you were shit out of luck. This issue gets exacerbated with the runes reforged update with chief runes being more important often than your champions kit or synergising so well with a champion that it completely breaks them by design, this is in no small part due to the fact that the balance team has been a bit more liberal with the allowance for things such as true damage, cdr and self healing all things that were ever since the early days of league gated and closely monitored in order to prevent incredibly unbalanced styles of play from emerging as the norm. Now adays any ad bruiser and will take conqueror and cut through enemies like butter completely devaluing resistances and rendering champs who are supposed to excel in tank busting obsolete. https://pm1.narvii.com/6642/375823073a06e17f60cc3520a86781809c63a29e_hq.jpg

Putting too much emphasis on something outside of a champions kit is bound to create situations where whole sections of the roster just don't measure up to what is viable i.e. what's currently abusing the runes and items the best. This game can be more easily balanced if the emphasis is on the champs themselves rather than external factors, I know this for a fact because I play a lot of heroes of the storm which focuses solely on modifying your heroes abilities as the game goes on in that game each hero feels unique and is capable of adapting to their situations without necessarily crowding out all other characters in their class.

Feel like a broken record, i know a rioter isn't going to read this and that posting this on reddit will get it buried by lcs posts so i don't know why i bothered, been saying this for years.