That's the thing with Greed, it's usually boundless and enough will never be enough most of the time. York may have everything she wants on Egghead, but why stop there when you can have any and everything you want in the entire world? Remember, as we've seen in this arc, Vegapunk was given a lot of leeway in what he could do, but in the end, he was still set to be punished for some of his actions. As a CD, York wouldn't have to worry about any of that.
The CDs have Absolute Freedom in the world. The way things are structured, they are figuratively (and literally) above everything and beyond reproach by the WG, the Marines, and, most importantly, the common individual.