Plus the fact is also that its worth believing it, its the future of all the currency's because its fully digital.
Bitcoin right now is just an alternative. And that's all. It has not yet proven to be "the future of all currencies". Even fiat is being spent digitally nowadays as people can use their banking app in combination with NFC. Does Bitcoin have a great future ahead of it? Yes! But as I said, things have to be proven in the coming years.