I only see one reason why Bitcoin became unstoppable, and that is because of its "decentralized" nature. Because of these features, no country can control Bitcoin according to the regulations they have. This is what strengthens, shows, or draws attention to increase the number of investors who buy Bitcoin.

I can't see any other reason why it is strong and unshakable, which is why it has been imitated by other cryptocurrencies that are also decentralized.