Social networks aren't that important to stay connected. In countries where there's still load shedding or shitty internet, people connect via whatsapp and gmail and you'll see advertising signs and paint on buildings and even cargo ships that just contain a whatsapp number and a gmail address.

That's their form of the internet, because everything else won't even load with speeds less than 100kBit/s.

Also: Whatsapp somehow works on dumbphones. I don't know how (yet) but there's apps for KaiOS, Samsung Bada and other old phones. I wonder if vendors reverse engineered the APIs and implemented their own clients.