I disagree. People will (somewhat) expect you to have a WhatsApp in many European countries, but hardly anyone will expect you to use Facebook.
At least in my circles Facebook is a wasteland. Many people haven't even posted anything in years, and if I was trying to reach anyone via Facebook I'd settle in for a long wait - until they check it in a month or two.
You won't notice it if you just open Facebook, because Facebook will fill your feeds with people who are active, but when I go through my list of contacts there it's obvious less than one in five are still actively using it.
I don't claim total knowledge of the situation everywhere, but I do keep in contact with people of a lot of different countries.
I do not agree with Chinese stance on democracy or human rights but I admire their willingness to play by their own rules. Not opening their markets and rolling out the red carpet for Silicon valley was wise.