Dollar is definitely finished, it's only a matter of time.
The only problem is no suitable replacement on the horizon: not yuan, definitely not ruble, not even gold.
Well, except for bitcoin.
Enormous wealth that's locked up in dollars will not disappear. It will flow somewhere. But where? If not into bitcoin, where?
Yes, bitcoin is where some of the value will transfer. The governments will still want their dirty fiat though. They will inflate away all of the debt and blow up asset prices until a reset is required. By then, most other fiat currencies will be gone.
If bitcoin is well respected by governments and politicians by then, it could form the backing of a new global dollar but I don't have that much faith in modern economists. I'll just hold bitcoin myself and trade it for the currency of the times when I need to buy something.