then they have the ability to host a website just as much as they have the ability to answer the phone
Many people in the developed world are behind CGNAT. Paying for an Ipv4 is a premium, and most businesses either setup shop on an existing listing page (e.g. facebook), or host a website from website provider/generator.
A phone number is public, accessible, and an AI can get realtime info from a scrawled in entry in a logbook using OCR