I don't think people realize how hard it is to balance league of legends.

It's not just "nerf this" or "buff that" it's "will this tiny change to X item result is a cascade of issues"

For instance. Armor pen on is nerfed. Suddenly etc, are all nerfed pretty hard since it's a big item for them.(or at least a very strong niche one) But what if you nerf/buff a big item? Let's say get's 10 less armor. Now it's considerably weaker against every AD champ and is a big nerf to tanks/bruisers that build it.

Another example. Corki hits a 45% winrate because of changes. Riot gives him a buff to balance him back out and overcompensates a bit. His playrate and winrate skyrocket. Because of this his lane counter, , hits a 53% winrate because corki is being played so often. Also he counters jinx, so now jinx's winrate drops below 48% and the supports he synergizes with get a nice small increase too. Now they have to find the right nerf for corki without touching caitlin, if they did, once corki was nerfed then she would be underpowered again (or at least when his playrate drops).

Now multiply this by x6 per patch for item nerfs and another x6 for champion changes and next thing you know, some champions just went below 50% and others shot above 52%