Google would eventually manage to completely block that. For example, have the app be encrypted for download from the Play Store for the individual Google-approved device key, and the device’s firmware will decrypt and run the app in a way so that the user can’t get hold of the decrypted app blob, and hence can’t possibly run it in any other (non-Google-approved) environment.

The bottom line is, the only way to ensure user freedom here is by regulation/legislation.