You are not forced to trust them. You can if you want to do things conveniently.

If you truly want it use its value then you must do it the correct way it should be done. Ideally you must compile your apps if you don't want to trust the distributor. There is no other option.

Propriety apps don't have their source code public so they could be collecting God knows what data and sending to the servers back at the company.

It shows the flaw in Google Play Store way of distribution of apps rather than signals.