I use Facebook, but don't have a phone number in my personal details, and don't have a phone number set for recovery. If I lose my FB account, I guess I'll be able to make clear it's mine, so I haven't set a recovery phone number, and otherwise - bad luck! It's not that important to me. I visit FB mainly using my laptop browser, Firefox with Privacy Badger.
On my Android phone I don't have the Facebook app installed, neither FB Messenger. I might open FB in my phone browser, which is Firefox since long, with AdBlock installed. I have used Instagram, but quit using it since they asked for my phone number.
I use Whatsapp, but use a special phone number for this. I do this mainly to keep whatsapp for private use only. Colleagues may use mail, phone and sms. My normal phone number is in my contact list, so I guess that's uploaded to WA, and probably to Instagram as well.
Now I'm wondering, in what ways can Facebook connect this all and know it's all the same person - me?
This all of course considering the recent sharing of data between Whatsapp and Facebook that's going on.