Not only is your location tracked 24/7 by cellphone towers, but also who you know. Not just who you call or text, but seeing what other SIM cards you’re standing near. Some may curse me out that I’m some kind of paranoid tinfoil hat, but as AI becomes more sophisticated, dragnet tracking of the entire population and drawing conclusions about your intimate behavior by relationship and location tracking will become extremely sophisticated to the point that no aspect of your life will be kept private.

This article goes over the basics of anonymous phone service and compares different plans. And there are no affiliate links: https://simplifiedprivacy.com/best-anonymous-phone-service-reviews/