From my thought own thoughts of things I don't think it's even possible for everyone to actually have bitcoin in their possession and it's not a matter of the limitation of 21million bitcoin available because I believe in bitcoin figure there are smaller units called the satoshi which if you actually calculate a person to a fraction of satoshi it will be more than enough to cover everyone there but my reason if saying everyone isn't going to have bitcoin is because we are humans and having bitcoin is a choice and the power to choose wrongly is always there as an option for many and many people will definitely go for that.