Yes, I think that Bitcoin can surpass the gold market capitalization in future not only surpassing it but it has the potential to reach 2x the capitalization that gold has. It's not going to happen within 4 years but I'm sure in a decade or two from now we may see Bitcoin surpassing market capitalization of gold or even reaching it's 2x capitalization by then.

If that happens then surely it will be a very good thing for Bitcoin. Bitcoin will be accepted all over the world if that happens and no country would pose ban or any restrictions on Bitcoin and its trading. By then if cash exists then people will directly purchase Bitcoin with cash because it will be widely available in each city and town. All online and offline services will accept Bitcoin as a payment method and people will give it more priority over other payment methods.