If (when) usd falls.
People will look for things to invest their money in to prevent their wealth from losing value as the dollar falls.
Many will buy gold, silver, jewels. Some will buy color tv's, electronics since they're not bad at holding value.
Others will buy bitcoin. It could increase demand for crypto which in turn would case the value and price of bitcoin to increase.
I, too, tend to the fact that if the dollar falls in price, a large mass of people with dollars, will look for an alternative in various international currencies of the world, perhaps even in bitcoin. But most still consider the option of buying gold, silver or mutual funds, shares.