I bet that in 5 years from now (even faster) Bitcoin or other cryptocurrency will join too.
That is highly unlikely.
First, Bitcoin would need to become a reserve for a country.
Its very possible that a government will create their own crypto currency. But you're right, for Bitcoin, I don't see that happening.
For me, that don't seem impossible. Let's say that in an Eastern Europe country, where corruption and devaluation are big, a libertarian could propose Bitcoin as an alternative national devise, he could win and apply his political program.