Where do you guys stand on the simplicity spectrum?

While I try to avoid using win rates as the be all end all for champion strength, I do use them to point out outliers in the department. For instance, from my experience, even playing at a platinum level, I still notice a direct correlation between champions who are simple mechanically (ex. Master Yi, Annie, etc.) and the amount of solo queue games won. For instance, ever since the most recent Lucian nerfs, I've wondered, where is the difficulty mechanically with graves? All of his abilities are very generous AOE's, and the rest of his kit is extremely simple to use. The fact that he's tanky as well gives him a slight bit of leniency when making mistakes. Applying the same logic discussed above, Graves is one of the strongest champions at not only a plat level, but the entire game, as his skill floor is pretty high, and his skill ceiling is pretty low compared to most other ADC's in the game. While I do think it's important to make some champions simple mechanically for newer players, when it reaches a point that the champions who are mechanically simple overshadow most of the other champions at a high level almost entirely due to their high skill floor, the issue turns from less of a problem of numbers into more of a problem of mechanical complexity.

TL;DR: Mechanically simple champions are way too strong even at a high level, and champions with a lower skill floor and higher skill cap are being overshadowed by the mechanically simple ones.

Do you guys think that it's okay for champions that are easy to play are still just as strong, if not stronger, than champions that are harder to play at a higher level of play? Let me know what you think.