I'm not sure how you missed it, it's right there in the summary: "Infinigen is entirely procedural: every asset, from shape to texture, is generated from scratch via randomized mathematical rules, using no external source..."

This is not a critique of what they achieved, but that is not an innovation over existing procgen techniques. Generating assets from maths is basically what the demoscene has been all about for decades.

The sheer scale of what this does, how general it seems to be (instead of a single special-purpose animation like in the demoscene), as well as the fact that the output is structured and labeled assets I would consider novel, and very impressive.

"without using any assets" vs "relying on no external assets" but it's not my area so I may be misunderstanding.

Ok, to clear it up:

"Ours is entirely procedural" == ""Infinigen is entirely procedural"

"relying on no external assets" == "every asset, from shape to texture, is generated from scratch via randomized mathematical rules, using no external source"

If that doesn't make it make it clear, could you elaborate on the part that doesn't click and I'll try and explain further.

Don't worry, I'm out of my depth and I know it, I shouldn't have put my oar in :)