According to the newly listed code changes, Google will take stricter measures regarding old apps being installed on new devices. Starting with version 14, Android doesn’t even allow sideloading of apps targeting older versions of the OS.

Currently, Google does not allow newly listed apps on Google Play to target versions of Android older than 12, but still allows users to sideload older software. . Google Play also lets you continue to install older apps that you have previously installed.
As already pointed out, Android 14 changes everything. Sideloading apps requires above-average technical skills using a command shell and new flags to allow installation. This prevents users from accidentally installing unsafe apps on their phones.
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