It'll be in 10 years, but we can clearly see it happening. If people still don't believe on bitcoin despite the price and it's massive exposure on mainstream then they will regret it in 10 years wishing they should've invented a time machine.
Not all governments are agreed to ban bitcoin or legalize bitcoin, like in Japan.
Still bitcoin is untouchable, I didn't see any of countries having a standard or at least metal hand law against crypto except banning it.
If what he meant was bitcoin as the currency that will dominate the world upon traditional fiat currency, it depends on people's choice.
Even if the government ban bitcoin, we can still use it by using a VPN to access overseas exchanges, yet bitcoin still can't accommodate a global scale at one time.
Decentralization might be favorable for all people, who does not want to take care of their own assets?