Bitcoin is limited and Gold is not.. They are both a store of value, whether it's physical or digital, and if you want to send value across the world it is way easier to send Bitcoin vs Gold, but realistically like Peter said what if something better comes a long?

Well there has been TONS of things come along (look at STEEM) that could be seen as better, but people still use Bitcoin just like people still use the dollar (IT IS THE MOST WIDELY ACCEPTED), and just like people use Facebook.. when the world finds something they all accept they seem to stick with it as long as it works, and the Dollar does not, but Bitcoin does.. and it can be forked if it needs to be upgraded, but only if the majority of the community agrees.. to make it better!