I cant even imagine how to track a person who has a cryptocurrency. If, of course, the person himself came and said all his data or trades large sums, then this may attract attention in transactions from his wallet. But people who trade not large amounts of cryptocurrency are not worth tracking.
I think they are only taxing the cryptocurrency exchange, because for me there's no way to know if you are a crypto user or not, you will just get caught when you broadcast it to the world haha, but yeah I think the crypto exchange is included and those who are running a business.