If what you want to maintain is contact with all those people, you can deactivate your Facebook but keep Messenger on. They're separate apps. It's worked wonders for me.
Confirmation bias aside, I've actually had people who neevr respond to email, don't use any standalone messengers, only read their private facebook messages weeks later... but are indeed replying to status posts and comments. So yes, you either stop communicating or adapt.
And no, phone calls are not an option. These are people I've never talked to on the phone in my whole life, why would I start now?
And no, phone calls are not an option. These are people I've never talked to on the phone in my whole life, why would I start now?