My experience seems to be the opposite of yours. Perhaps it's a geographical thing?
Personally I don't know a single person that uses Hangouts, the one time I sent a test message to a friend, they phoned me to ask what it was, why had this stage app they knew nothing about suddenly say "Hello, testing 1, 2 3"!
Almost all my friends now exclusively use Facebook messenger, and generally won't answer to SMS texts.
Personally, I only use SMS messages, and don't have anything FB apps installed on my phone (and being a Nexus device, it wasn't pre-installed either).
My fiends grumble when it takes me 2-3 days to reply to a message, as that's the typical gap between me checking into the FB web site, which I only do on my PC, at home, when I can be bothered to look.