I don't agree that the U.S. is going bankrupt, Robert Kiyosaki has been saying this for a long time now and i believe he is amongst the people who believe in de-dollarization and the failure of centralized assets. He believes BTC will get to $2.3, but he has not said when he thinks that will happen, i don't know when BTC will be able to rise to such an amount, maybe in the far future.
The US is still a global power, I don't think it is very likely that it will suddenly go bankrupt, but if we look at history, we see that global reserve currencies are constantly changing. This inevitable end will happen to the US dollar one day.
However, in the near future, the world may enter a situation that it has never been in before. Instead of a global centralized power, we may witness regional hegemonies. I don't think it would be easy to make predictions about this situation, but I am confident that such a change will pave the way for Bitcoin.