What will happen on BTC if the government will said that all the bitcoin holder have to pay their tax??
Maybe the expansion of BTC community will get low than usual.
Trade profits are already being taxed. Crypto tax already exist. It's part of a needed regulation that could actually help increase adoption contrary to your statement. You can't expect to make profit and not pay taxes.
Exchanges are the one who are paying taxes for us, But in U.S if you have profit through cryptocurrency you still need to declare it and pay the tax. Its ok to pay taxes because its really mandatory if there is already a regulations, no way to escape it but to follow.
a). people will just pay taxes.
We really have no choice if its already a law.
b). people will move to other country.
Quiet expensive especially when you only have small value of bitcoin or any cryptocurrency.
c). people will exchange their Bitcoins fro something else that will not make them pay taxes.
Mostly they will spend their bitcoin so the profit they will declared is quiet small.