By creating a deposit on a cryptocurrency exchange, you are actually transferring bitcoins to the exchange for storage.
If all people liquidated their bitcoin deposits, cryptocurrency exchanges would probably not trade bitcoin. They will trade Ethereum or other cryptocurrencies. Bitcoin was created by the legendary Satoshi Nakamoto. He did not consider it as a commodity sold on centralized cryptocurrency exchanges. Bitcoin is a decentralized protocol for transferring value in the virtual space. It has value in and of itself.
That is why, in my opinion, the collapse of the FTX cryptocurrency exchange in the long run will not have a negative impact on the price of Bitcoin.
A cryptocurrency exchange can exist without Bitcoin, and Bitcoin can exist without cryptocurrency exchanges.