You are wrong, although I don’t know the exact mechanism. I once witnessed first-hand a somewhat shady situation where a private investigator was trying to find someone’s whereabouts for the purpose of serving them for a lawsuit. As a last ditch effort, they reached out to a somewhat shady contact who was known to have some kind of internal access to the phone system and gave them the target’s phone number and sent $200 with Paypal. 10 minutes later we get an email back with a specific address and as it turns out that address was the target’s lawyer’s office. One of the process servers goes over there and catches the target on his way out.

I was a bit shaken. I believed what you believe before then too.

Edit: Looks like it’s LBS/LCS: https://www.telecomhall.net/t/what-is-lcs-and-lbs/6374