In order to argue that, you have to list your goals, what you want to do with your phone, and the goals of an attacker. On Android, other than a few minor inconveniences, I can still achieve everything I want to with my phone, where an attacker will have a difficult time achieving their goal, of presumably stealing some data from another app.

This is compared to PureOS where you may have free reign, but so would an attacker if you install their app on your device. If you used QubesOS I'd argue that restricts the user a similar amount as Android does, not to mention missing out on a number of mobile friendly apps.