That's only true today. And it's quite difficult for artists by comparison. I don't think people will bother with the complexities of polygon based graphics once they no longer have to.
Not really. Look at how many calculations a single pixel needs in modern PBR pipelines just from shaders. And we're not even talking about the actual scene logic. A super-realistic recreation of reality will probably need a kind of learned, streaming compression that neural networks are naturally suited for.
They already are. But the future will probably not look like this if the current trend continues. It's just not efficient enough when you look at the whole design process.
As I said twice now already, efficiency is not just a question of rendering pixels. When you take the entire development lifecycle into account, there is a vast opportunity for improvement. This path is an obvious continuation of current trends we see today: Why spend time optimising when you can slap on DLSS? Why spend time adjusting countless lights when you can use real time GI? Why spend time making LODs when you can slap on Nanite? In the future people will ask "Why spend time modelling polygons at all when you can get them for free?"