Of course, this option is not excluded. The government can impose a tax on every transaction in bitcoin. I read that this happened already in Poland. There, citizens were required to fill out a separate document for each transaction in bitcoin and transfer this data to the tax authorities, that is, all the difficulty in collecting such information was shifted to the shoulders of the citizens themselves. This caused massive dissatisfaction and indignant citizens are organizing a protest there. How this will end, we'll see. However, if the tax authorities themselves collect such information, then this is unlikely to be possible. It would be more reasonable to set a minimum amount of a transaction in a crypto currency that would not be taxed, and this amount should be decent enough to free everyone from fixing small amounts that do not greatly affect the size of the future tax.