I think it's just that in the past, you would need X free time, Y motivation level, and Z skill level (partly tradeable for X and Y) to create something like this, and now all of those values are smaller. So it's 'economics' in the straightforward sense, because not everyone could afford to spend X hours on something they weren't going to monetize, and also in the sense of the incentives shaping people's productive/creative activity.

(As for whether it's a good thing, I'm conflicted. It's cool to see more stuff like this, but if it crowds out the more intense passion projects, we lose something too.)

I believe that part serves to emphasize the main point.

To elucidate for this particular example, before AI agents existed, projects with this level of data and depth might've needed to be monetized in order to justify the resources to bring it to life.

Now that the barrier is much lower, the creator didn't mind spinning up and providing it with no monetization (e.g. no ads).