Even bitcoin's adoption is still low, just imagine what bitcoin's price growth will be when the entire world accept bitcoin as an alternative means of payment and every institutional investors are accepting it, 1 million for a bitcoin will be easy.
I agree that it's still low, if it covers most of the population of the world then it will be reaching that price very easily soon. We're not in a hurry but we all knew that it's going to happen.
My future prediction is that, by 2040 we'll be seeing bitcoin catching up to gold's market cap, slowly but sure.
That's 15 years from now on. I think from that span, there can be a lot of things that can happen so rapidly. With the adoption that's happening with the governments and financial institutions.
It can even be lesser than that but it's a safe bet.