If I must be honest, I do not think that the bitcoin will be used by everyone in 2022, we cannot also not predict this either but its just something that I do not see happening these days.
The bitcoin has a great future a head of course but I do not think that other currency's will me less more used.
Its not about other currencies, nor it is about governments & all, but still it does not seem to be possible that the whole world would use bitcoin by 2022, we can even does not predict if bitcoin would become more popular in physical world by then because these things are mostly unpredictable.
Well Bitcoin's Demand and Legality is a big factor for us to consider if Bitcoin will ever be use not replace Fiat. Also Bitcoin's transaction takes too long to confirm in which making business slow, Every minute of a businessmen is important to them. The demand of bitcoin depends on how it will be popular to new and upcoming users because they are the ones who will trigger people into trying bitcoin.