This is the measurable evidence you are talking about: https://a16z.com/revenue-benchmarks-ai-apps/
Here's even earlier evidence: https://en.wikipedia.org/wiki/Tulip_mania
All three companies profiled are selling products TO vibe-coders, not apps created BY AI-utilizers.
The shovel seller in the gold rush analogy.
Here's even earlier evidence: https://en.wikipedia.org/wiki/Tulip_mania