Aren't NFT's literally just jpeg files?
The power grid stuff is also confusing to me. Generating electricity isn't a carbon emitting process in theory. You can generate power from solar panels, or hydro-electric generators. I don't see how crypto is "poluting" in any sense other than power sucking off a grid that needs to be used fairly evenly over a section of population.
NFTs are jpegs with a special trackable ID. So yeah basically just jpegs but jpegs you can grift people into paying their life savings for.
As far as power generation, I mean you're not wrong that we do have clean energy sources as options, but a lot of places don't particularly have them in place yet. I live in Canada, a wealthy relatively progressive country with massive tracts of stable unused land that can easily have solar, hydro, or wind put on it. But we're only just getting there - if someone brings a crypto plant online there's a really good chance the power is gonna come from a coal or natural gas power plant.
If you do something to massively increase the power demand in an area, whether you're putting on a sick laser light show or mining crypto, then you are causing more coal or gas to be burned and effectively polluting. The issue with crypto is that it's basically a constant extra demand as opposed to most other high energy events which usually follow cycles or are just brief in general.