Again, why are you focused on medium of exchange. It is only one function of money, and in today's world the least important. We have a medium of exchange that currently works, for most people; why would Bitcoin replace it already?
I use Bitcoin when I need it, and it works. I needed ivermectin and antibiotics, and I wanted some watches from russia. Bitcoin was the only way I could get those things. Adoption is not something that needs to be pushed. People will recognize superior money and choose it over inferior money.
Hard money will impoverish those with softer money. It has happened many times through history. Africans, Indians, Chinese, the Yapese...
A world where Bitcoin does not impoverish the holders of all soft money and money substitutes seems extremely unlikely.