This will kill gamers immediately.
Imagine now I own 2 gpus. Im already paying tax for the 2nd card, if I'm going for my next build in future or if I wanna upgrade, I pay tax again for my 3rd GPU?
The only thing that make sense is to tax those miners. Not on GPU, but their source of extra income. But that is if the govt of each country can or would tax them accordingly.
Apart from that, even if they tax miners on GPU based, they don't even care, cause to them if they are earning well, even if gpu were to be tax, they will still continue to buy.
It's just like our ERP gantry. They can charge us as high as $6, but if we got to use the road we got to use that road.