There's only so much of it to spend before they run out.

I don't pretend to have detailed domain knowledge here, I may have seen other people's GenAI output rather than reality*, but the numbers people are throwing around for this stuff sum to trillions of USD, slightly higher than other (same caveat, perhaps also GenAI output*) claims I've seen about the total supply of money in the global venture capital markets.

* I miss the days when I could make a decent guess as to which websites were reliable and which were BS