For me, it doesn't matter what percentage of taxes will be applied to cryptocurrency earnings. For me, there is no doubt that this will lead to a decrease in the popularity of all cryptocurrencies. The flight of major bitcoin owners can significantly reduce the capitalization and popularity of cryptocurrencies. Any intervention by the state is a negative signal.
It will just add another confusion to the popularity of bitcoin until all countries accepting bitcoin tradings will have implemented taxation on crypto related earnings. Although its a sign of good market of security but investor will decrease our market cap because of this and it will be impossible for bitcoin to reach its altime high again.