Re: Oh the irony!
"Don't join Facebook, and they have no data to use or share"
Not exactly true..
https://www.theregister.co.uk/2018/04/17/facebook_admits_to_tracking_non_users/
https://www.theregister.co.uk/2018/05/22/facebook_data_leak_no_account/
I'm sure there are also other examples - I couldn't find the link to the article about FB collecting data for people who don't have an account, from the phones of people who do.