Why are Garen, Master Yi and Annie the only champions allowed to stay simple?

I keep seeing rework after rework literally removing champions from the game. I don't mean heavily changed I mean absolutely no gameplay concepts staying from legacy to new.

Yorick is one of my favorite examples. The simplicity of raising the dead with empowered auto attacks was a simple kit. His ultimate was a little more in depth but it wasn't rocket science. I'm still butthurt about my main Urgot being removed. The e locking on was probably the most complicated thing on him, That and his 25171 stat effecting abilities. Poppy was also pretty simple, Other than positioning and situational ulting. (Ugly as sin though)

I just have to ask. What is wrong with simplistic designs and easy to play champions? And yes I left out other simple champs and yes I left out other major reworks. Edit: YEAH I KNOW THERES SIMPLE CHAMPS OOGA BOOGA. Yes thank you for showing me other simple champs as well thanks who woulda thought it