Can someone please explain a bit what is included as part of a “unique identifier”… does it mean the app sends Google what communities you’re visiting or content you’re consuming, so they can advertise to you personally?
Starting with Android 12 (and maybe earlier, I think it may be a part of a Google Play update?), you can delete your advertising ID in settings - definitely worth doing!
Unique device identifier would be some information unique to your device that can identify it. A common example of such a unique Id would be your IMEI although that isn’t necessarily what they are using. Minecraft as an example creates a unique user ID based on your account that system administrators can use to keep your player records even after you change your Microsoft account name or gamer tag.
It doesn’t have to be specific data related to your activities in the app per se, but it could potentially be used in that manner depending on the app.
This is present in all apps in the playstore for serving ads. If you are running away from it you have to run from the entire internet. You want to live a life like the people in privacy sub reddit with that tin foil hat. For the developer to serve ads this is necessary.