In my opinion it is not possible that by 2022 everyone will use Bitcoin.
If you look at the % of people that have access to internet we are now at about 47%. (
https://en.wikipedia.org/wiki/Global_Internet_usage)
Hence first everyone in the world should get connected before Bitcoin can be used by everyone.
If we reach a doubling of the users of Bitcoin every year I guess we will be at about 1 billion users... pretty huge number though.
Just in three years. But for example most of the people at the age of 55 are not very good users of computers and it is very difficult for those of them who don't have any connection to finance to even understand the core idea of bitcoin. Why and How should they use it?