There was a time when I thought bitcoin would fail. Then a friend pointed out to me how many people have invested so much money in the ecosystem. They won't let it fail.
There's a whole industry out there. There a miners, there are mining device manufacturers, chip and board creators, there are exchanges, wallet creators, physical coin makers, loan services, advisors, software developers, pools, and this is only touching the tip of the iceberg.

Put it this way - gold will fail before bitcoin. Fiat will long fail before bitcoin.