because bitcoin system was so protective and people in all country starting investment everyday, it makes bitcoin can survive from extinct
You already answered your own question. Lol but anyways on my view for me why bitcoin can be a future currency, it's because crypto currency value nowadays is higher than fiat money so how much more in the future? Maybe it will be on ATH again because of being popular, which is a big help to convince more country to regulate again crypto in the future, And also because using crypto you can do different manner in easy ways such (paying bills, sending money to family , buying stuff through online and etc ), without going outside just using online wallets and internet. .