I used to think similarly. However in the past 4-5 years I have observed closely my non tech family member's usage of smartphones and they frequently install to

I used to think similarly. However in the past 4-5 years I have observed closely my non tech family member's usage of smartphones and they frequently install totally random apps, they have no idea what their default browser/keyboard is at any moment or how to change it and who frequently receive apks on whatsapp and almost always click on it (only the android hurdle against apks protects them) so on. Sure it might be fine for gmail to write OTP but what about abcdmail, what about go pro SMS style apps. I think there is a fine balance here between flexibility and non tech user safety.