Worst of all, the actual phone call app. Why much I jump through countless hoops just to make it so a third party doesn't have the ability to take over the ful

Worst of all, the actual phone call app. Why much I jump through countless hoops just to make it so a third party doesn't have the ability to take over the full screen and audio of the device I was actively using? Ideally an incoming call would only vibrate the device briefly and put an icon in the status bar. That's it. Instead, I don't remember what I did anymore but it's completely suppressed on my device now. It's actually worked out OK because I don't give my number to anyone new and anyone who does know it also knows by now that I don't pick up and to contact me some other way. Means that ~100% of incoming calls are spam and my device is correctly filtering them all to /dev/null