Some versions ago, it was possible (at least on lineageos (or was it cyanogenmod?)) To change wayyyy more permissions. So many, one could break the system into not bootable anymore.

They removed this, because permissions now are just a way to let users think they would have control.

If I understand correctly the reason for this is actually because what permission says it does on the surface does not always equal what it actually does. For example the phone or location permission might not literally be necessary but the app might have some reason to request. For example some of the permissions on Android are tied to using the sensors and radios and such. Also some developers are just bad and ask for permissions they don't need. They shouldn't do this but I'm a comment not a cop.

The strongest example is location. On older Android versions, apps doing things like Bluetooth or Wi-Fi scanning often had to request location permission even if they did not actually care where you were. That was because nearby Wi-Fi networks and Bluetooth devices can themselves be used to infer location. Android later split much of this into dedicated “Nearby devices” permissions: Bluetooth got separate permissions in Android 12, and Wi-Fi got NEARBY_WIFI_DEVICES in Android 13. Some Wi-Fi APIs still require location access.

For a game of that era, READ_PHONE_STATE could have been used for things such as reading call state, obtaining a device identifier, analytics/licensing, or by a third-party SDK bundled into the game. Before Android tightened this substantially, READ_PHONE_STATE could provide access used to obtain persistent identifiers such as IMEI/device ID.

I'm sure android has something for telling apps that a fullscreen notification is being displayed.

You'd think that notifying an app that it's being interrupted due to a phone call would be basic functionality on a phone. The kind of thing an app doesn't need permissions for because it's core OS functionality that exposes no information to the app other than that it's being sent to the background for a moment.

I have no idea how Google thought that this is advanced functionality equivalent to making phone calls.

It's probably to gather your phone number.

I just checked and it's possible for audio interruption notifications to ignore other audio sources but not calls or notifications without the call permission. The game could be smart about it and assume interruptions that last more than 2 seconds are calls. There would be a delay but I think that'd be fine.

Anyways, pretty sure the grand majority of the apps that used to ask the call permission wanted it to look up the imei.

Yes I think that is the reason, and yes, there should be an automatic thing or other permission at least