[gwern]

I would call it just "demand elasticity". Jevons paradox is a subset of demand elasticity where there happens to be some relatively fixed 'resource' like oil. There's no 'resource' equivalent for something like video gaming; it's just demand for writing games is elastic and when a game gets easier to build, people demand more supply, which comes into existence then.

[ghaff]

I actually think it's more like "supply elasticity." It gets easier/cheaper to create something and you get more of it--possibly at lower quality (as is generally the case here because there aren't any shortcuts to having good game mechanics).

Demand may or may not go up but, in any case, it's probably harder for the user to find the gems among all the clones and drek (and harder for the gems to gain attention).