Bill Walker it could be that there is a hypothetical "ceiling" on a per state, per county, or per region basis.
For example... we know there are many investors making over a million per year, but the only way they've been able to do this is to develop some expertise and market knowledge in the markets where they're working, and everyone has limited capacity in this sense. You can't be a expert in every market, there's just too much everchanging property and data out there.
So in a sense, as long as a land investor is only willing to flip (without doing any improvements or subdividing to create new value), even with the great margins that the average land deal has, a land flipper's income will be limited by the number of markets they're able to learn inside-and-out.
Not to mention, some markets perform better than others... and being an expert in Market A may not be as profitable as being an expert in Market B, if that makes sense. So there's also a bit of good fortune involved when an investor picks a great market, becomes and expert in that market AND they continues to work it hard.
Giveh what you mentioned about the Bosch interview, you might find this one interesting: https://podcasts.apple.com/de/podcast/182-our-most-open-interview-yet-tantalizing-entrepreneurial/id1287225837?i=1000484709925&l=en
This is from Austin Peek, who has one of the best podcasts I've heard in the business/entrepreneurial space. Definitely worth subscribing to.