I think it’s also worth noting that we’re talking about variation in a pretty narrow band. 4.4s and 4.3s for unadjusted HGs, 4.6s and 4.5s for CoGs before the 2023 dip. That feels to me like the scale of variation that you can expect from the normal vicissitudes of taste, and not necessarily something to draw big conclusions from.
If the two 2s drag down the average for 2024, that’s in significant part a consequence of new writers trying to do new, much more linear, and ultimately unpopular things with the medium. I don’t think we should lament that because it drags down an average that most readers will never see.
The big picture over these years is also one of significant overall growth in the audience for these games, and blockbusters (both HG and COG, but especially HG) reaching sales levels that would have been impossible in earlier years. I don’t think overall HG authors should be afraid or discouraged. This is still, by far, the best place to find an audience for your interactive fiction.