I don’t believe Bitcoin will ever drop to zero, but I agree its value could drop considerably when something else comes along, the real final currencies of people, doing something similar to Bitcoin, a personal form of money-as-sunlight, automtically marketed and representing our personal value, in the same way as stocks and shares.
As we can see Bitcoin is the sun doing work for us, our very own sources of money-as-sunlight can replace the labor of all people, whilst giving all an equal chance of success, in a true meritocratic democracy, none gaining at the expense of any other, since all money is free and infinite, powered by the sun, the only real source of energy and wealth, whilst repairing all environmental damage, there will no longer be any need or advantage to possessing capital, and the science of investing for profit becomes something relegated to embarrassing history.
The power might be taken from the banks by Bitcoin, and then it will be up to people, the vast numbers of whom will be owning Bitcoin by then, to recognise it is only right that we declare all world debt to be actually an energy debt to our planet, which can only be paid back down by money-as-sunlight for all people, their very own individual currencies.