A paranoid part of me has wondered if some of the text/phone spam we all receive is actually used to stimulate cellphones for tracking purposes. If you have deeper access to the OS, then fingerprint unlock or FaceID also seem important for positive identification prior to, for example, a Predator strike.
I don't think so. I'm German and receive the spam, even though I can be tracked using SMS messages that aren't shown on the display at all. https://en.wikipedia.org/wiki/SMS#Silent_SMS Plus, you can always ask the carriers to which tower(s) a phone is connected and simply triangulate from there, without sending any (user) data to the phone.
"Phone call for XYZ", "SMS for XYZ", "Establish TCP connection to XYZ". Every single device that hears this has to decode the message to the point that it can say "Nope, this isn't for me. Ignore". You've got billions of devices online at once, doing things that require messages to be sent to them. The network has to find a way to broadcast these messages to the tiniest geographic area that it possibly can, or else the whole thing breaks down. So yes, there are plenty of completely normal, standard ways that the network can make your phone say "I'm over here" without anything showing up on your screen.
(I worked at Motorola in infrastructure tech for many years)