Here are some scenerios that can cause the price of btc to fall drastically. (In my opinion, it is highly unlikely and the possibility very slim).
(1) No way to trade bitcoin or exchange it for goods and services.
(2) All governments of the world placing a ban on bitcoin and bitcoin related activities making it highly illegal.
(3) The entire bitcoin network and nodes going offline making it impossible to even make underground transactions in bitcoin.
(4) Another crypto overtaking bitcoin and value and more people shifting investment to this new crypto.
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Lol (1) No way to trade bitcoin or exchange it for goods and services.
(2) All governments of the world placing a ban on bitcoin and bitcoin related activities making it highly illegal.
(3) The entire bitcoin network and nodes going offline making it impossible to even make underground transactions in bitcoin.
(4) Another crypto overtaking bitcoin and value and more people shifting investment to this new crypto.
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from the list you have here only number one is what I believe can make price of bitcoin drop or maybe kind of render it useless, because if there are no ways to exchange bitcoin, and all exchanges , both the centralized and decentralized exchanges, are no longer functioning, it will affect bitcoin. But even if that happens I think people will still be looking for ways that they are going to move it, which I can’t tell, but whatever happens, let’s not wish for something like this lol.As for the number 2, the world governments all placing bans on bitcoin is not going to stop anyone from making use of bitcoin, people are still going to be making use of bitcoins when there is a ban, it doesn’t stop anyone from making use of it, people are still going to be using DEX, because DEXes are definitely still going to be there and people can also make use of p2p methods to trade. That is the same thing with that number 4, another cryptocurrency overtaking bitcoin wouldn’t cause it to drop to zero.