Simple, really. Google is an ad company, while Apple isn't. I have no idea how Google analyses behavioural patterns etc, but it pleases me to think that perhaps I somewhat reduce the number of times I become a data point for them (same reason why I don't use their search).

c) Why don't you de-google an Android phone, plenty of OSs to choose from?

My bank app and national e-id won't work, or so I heard. Plus, I do enough tinkering with my xmonad config, emacs init file, and all that. Simply no energy or interest left to spend on mobile, which to me is relatively unimportant.