Directly taxing AI is very hard. Imagine if a company had to pay taxes for every AI agent operating in the U.S. or the E.U. As if they were regular employees. Big corporations would simply move the AI agents to countries without taxes.
Let's say EU and US taxes AI tokens. India doesn't, so almost all prompting done by international companies now is outsourced to India, and still not taxed.
Or do you tax AI companies and tax tokens "at source"? Then, obviously, they either lose competition with foreign (let's say Chinese) companies that do the same but are not taxed, or more likely all AI companies move out of EU and US.
I guess the other countries can slap sanctions on them, but the people benefitting won't care really.
I can only image the Kafkaesque tax code the government would come up with. Then it would create all sorts of weird incentives as companies attempt to minimize tax paid.
This is not a reason to stop taxing (i agree with most here that taxes should be higher), but to design taxes that can't be circumvented easily.