Can Bitcoin replace the Dollar?

At its inception, one Bitcoin was worth less than a hundredth of a US Dollar. Today, one Bitcoin is worth around $4,000 US Dollars.

Given the explosion of the value of a Bitcoin in 2017 in particular, many forecasters have speculated about the potential for Bitcoin to be worth $100,000 USD one day. When I see forecasts like this, a question comes up in my mind: could it ever happen that so many people put their USD into Bitcoin and other cryptocurrencies that these currencies would render traditional fiat money obsolete?

After all, any currency only has value insofar as people think it has value. If everyone agreed that pet rocks should be considered the primary legal tender of their tribe, city, state, or country, then pet rocks would have a lot of value. Similarly, if an ever increasing few people placed value on the US Dollar, the Euro, or other fiats, then these currencies would lose more and more of their purchasing power.

Of course, the one hitch in this theory, a hitch that could correspond to the potential of the cryptocurrency market as a whole, is if the central banks use the power that they still have to force fiat currencies to remain the sole currencies of legal tender, likely through military force. This would really only be another response in the centuries- (or even millennia-) long battle between the common peoples of this world and the bankers, the one percent, the ruling class, whatever you want to call them.

While I recognize the definite possibility for banks to use their puppet governments to fight back in this way, my personal feeling is that any such attempts would be a last desperate ploy from a dying cabal, rather than a permanent reversion to the old state of affairs.

What does everyone think about the theories I've laid out here?