You are right, if the security sandbox is broken, then you have lost control. But at the same time, you also know that only 0.3% of the Android user base is us

You are right, if the security sandbox is broken, then you have lost control. But at the same time, you also know that only 0.3% of the Android user base is using this year's version, and less than 25% are using last year's version. The security design of the app should reflect this.