People who owned bitcoin they'll sell it since the price will become double and they will make a smart profit.
After that, all the bitcoin clients will move to other cryptocurrencies. Ethereum is the second-best cryptocurrency and it will become the number one crypto.
If all the bitcoin gets bought up it will increase the other cryptocurrencies price too.
So you believe that ethereum will become most valuable cryptos once every bitcoin was sold? If yes then its just stupidity to be honest because if there is no more bitcoin to buy then the price will be in peak so bitcoin will be high as now but for sure this will help other cryptos to increase as well.