Comment by lern_too_spel

You can develop and install via adb, but you can't just tell the package manager to install an APK you downloaded on your phone. Maybe attestation makes sense to allow Amazon App Store or Epic Games Store to be installed without a warning and to allow companies like Spotify to distribute their apps themselves from their websites without using Google Play Store and without a warning. What's wrong is preventing people from installing apps that haven't been attested by Google straight from their phone, even with a warning.