Bitcoin is becoming more and more common. But there are a lot of people who don't know Bitcoin. It's unreasonable to think that all of these people would buy bitcoins. I don't think that's gonna happen. However, more investors can enter the market than today's investors.
I also think so, that the usual knowledge about BTC is not enough. Although most people have heard about bitcoin, they do not know what its advantage is over the dollar. In addition, there is still a difficulty for many to make a payment, because it does not work like a credit card.
For me 6.2% only of American are using bitcoin because they dont need it and also the crypto world. Wanna know why? Its because they are one of the most progressive and rich countries all over the world and each of their citizens earn a lot of money because of their high valued dollars. Believe it or not even the maids and gasoline boys on US are rich because of their good salary and because of that I dont think many of them will prefer trading here in the crypto world.