I did the opposite, went from Android to iOS because of security. I'd rather live in this "walled garden" instead of the vulnerabilities that pop up in Android now and then, the malware that's always popping up in their app-store, and finally the fact that Google is always looking over your shoulder at everything you do, even despite how much you "turn off" things in the OS, it still phones home. Microsoft is the same. I'm tired of it. Not to mention that Android manufacturers idea of an "update" to the OS means you basically have to buy a newer model, as they often lag months behind on software/security updates from Google, and Apple supports their phones and tablets with updates years after. For instance, Google only provides updates to their Pixel phones for 3 years. Meanwhile, my wife's iPhone 6s is still chugging along with the latest OS after 5 years.

But this is just me. Everyone should use what they are comfortable with.