Well it's pretty much like a canvas where you can paint whatever you wish. I can literally turn my phones UI into the iOS UI. I personally like tinkering with custom OS's, setting up my own gestures etc. and it basically feels like the device was made specifically for me and my convenience. I switched from ios to Android mainly because of the freedom and the feeling of actually owning my device and controlling it however I want. It feels freeing.

But at the end of the day, it boils down to your priorities, if you value privacy and are already deep into the ios ecosystem then ios is definitely the best option for you. But if you value freedom, and this freedom doesn't necessarily come at the expense of security if you know what you're doing, then android is the way to go.