I think that's mostly training costs. There is a serious level of diminishing returns and the primary way companies have been trying to get ahead is throwing more and more hardware at it. AI already burns something around 5x as much power as crypto mining and it's only growing.

You hear sometimes about the AI singularity and how they will continue to become smarter at an exponential pace until they're basically gods in a box, but the reality is we're already well into the top of the S curve and every advance requires more effort than the one before.