[deleted] but it isn't invulnerable to network based attacks and potentially allows third party app data extraction and exfiiltration.
I'm not sure how that makes smartphones more vulnerable than desktop computers. Smartphones were designed with security in mind and with a mature foundation. If anything, desktop systems are more vulnerable to the example you provided.
The SELinux permission model is quite strong on Android compared to the weak/nonexistent model on desktop systems. There are also app sandboxes which as far as I know don't exist on desktop.
And there are many other reasons which I won't go into.
Your best bet to storing sensitive data is on an encrypted drive with the sole purpose of storage, or a user profile on the phone.
But bear in mind (I just saw this):
Carlos-Anso Its possible, though rare, for apps to elect to have keys in the HSM to encrypt their data. In this case the app could have the HSM keys destroyed or you could clear all storage for, or uninstall, the app and the data would be unrecoverable.