Unrealised capital gains tax requires some way to assess the value of assets. This is a lot harder than it sounds.
It already exists in the form of property taxes, which are quite unpopular.
at least all financial assets (stocks, etc) are easy to assess value so why not start with that? same with gold, silver etc. Some minimal amount you can make it nontaxable to reduce administrative burden.
>It already exists in the form of property taxes, which are quite unpopular.
For an unpopular tax, the property tax is remarkably ubiquitous. Are there really any popular taxes?