In my circles, I hardly know of anyone who does not use it.
TikTok is omnipotent for the under 20s.
Most small business have one or more of a Facebook, Twitter, Instagram, Tik Tok, Linked In account.
Then there are Snapchat and Only Fans too.
So much of mainstream media news is gleaned from social media, and regurgitated.
Just from a quick Google search here is a stat.
https://blog.digimind.com/en/agencies/facebook-uk-essential-figures#:~:text=Facebook is the most used,66% of the country's population.
"In the UK, about 44.84 million of the estimated 67.9 million individuals who call the UK home use Facebook regularly, or about
66% of the country's population."
I mentioned social media because of the photos of Nichola Bulley I have seen in the press.
Selfies, or couple selfies, of walking the dog by the river etc.
To me a routine activity in no need of broadcast, yet it was captured by cameraphone.
Suggest to me that Facebook and Instagram played a notable part in this couple's lives.