That's part of why I still gave phone numbers and emails, despite both not being secure in any capacity; most people do have them, even if they're not their preferred methods of communication.
I did lose a couple of people, but they were the ones I caught up with like... Once a year, anyway. Not that I didn't value them as friends, but there comes a point where it's like... I'm not missing a whole lot without you here, y'know. And it's not like I had that many friends, either, I only have a handful of people I talk to regularly. Maybe 15-20 a month if we're including friends of people I know who I see in passing?