because bitcoin system was so protective and people in all country starting investment everyday, it makes bitcoin can survive from extinct
Well Bitcoin is a currency now, and main changes in the future around Bitcoin will be regarding mass adaption. Such transition will only happen though if Bitcoin can solve problems regarding mining and transaction fees, as they are to high for small payment as they will sometime result higher than actual purchase.
It will be so hard or almost impossible for bitcoin to be the currency world wide. As we can see, many governments aren't allowed for such thing to happen.