This is literally the exact thing you requested, which was:
> Can you point me to the effect on earnings of the customers of said AI tools
Just looking at the overview of Levels' ventures listed in the Bio:
http://PhotoAI.com $141K/m
http://InteriorAI.com $29K/m
http://RemoteOK.com $34K/m
http://Nomads.com $14K/m
http://levelsio.com $14K/m
http://pieter.com $6K/m
You can see that his old ventures (which he has built over many many years) are bringing in less money than his new ventures (built over fewer years). How is this not "effect on earnings of the customers of said AI tools"? Levels is a customer of AI tools. His earnings have gone way up as a result of AI tools.