Notice how in the last several years, a lot of popular sites have allowed signing up with phone numbers, no email address required. Besides making the service more accessible to a generation that doesn’t use email, getting a person’s phone number is great for profiling them for advertising reasons.

In many countries, either WhatsApp or a PSTN number for receiving an SMS is used today for the things that you think are done with email. I have lived in two countries that have highly digitized government services, and they were provided over an official app where email wasn’t part of the signup flow.

Sure, maybe some people use email at work (but WhatsApp has eaten into even that in some regions), but then that address is so associated with work that they don’t use it for social contacts.