In this case it's as easy as sending automated threatening letters "we see you've done X Y and Z transactions, we think these are taxable, please provide paymen

In this case it's as easy as sending automated threatening letters "we see you've done X Y and Z transactions, we think these are taxable, please provide payment amount A or appeal it by doing B" The rich people and rich companies (10lb trout in your example, since it may not be clear to everyone that 10lb is no small trout) have big enough dollar amounts at stake to be worth fighting for and will fight but the cost of running that process will be just a formality compared to all the $100-500 checks they'll receive. I don't think it's about the surveillance aspect or the money except as a means to the end of having more power to control who gets economically marginalized. Look at the difficulty the government had enforcing executive policy and controlling the narrative during the pandemic (compare with the first few years of the war on terror for example). They don't want to get caught with their pants down the next time around.