I am thinking can't bitcoin coexist with the legacy financial system. Because it can either take it over, or it will fail. It's hard for me to see bitcoin value still high in 2019.

We have not seen any "here to stay" bitcoin companies besides coinbase, and maybe bitpay but I am skeptical about them.

All of these other companies that got media attention have not reached the point where you can see them around in 5 years. I expect 75% of them to go bust.