This post is conjecture without facts.
There are facts.
Three million people live in Iowa. 325 million live in the USA. For Iowa to be noteworthy it would need (3/325 x 7.1) 72,000 millionaires to be better than average. It has 71,000, putting it squarely in the middle.
Statistically, there are millionaires in Iowa. There are not millionaires in Iowa because they've cracked the code or some shit.
Years ago I met two brothers who started a sheep shearing business while in high school.
They’d go to farms, charge some nominal fee (like $2.50 per sheep), and then keep all the wool. Why? Because wool is worth about $2 – $4 per pound, and the average sheep carries 20 – 40 pounds of wool.
So you’re gaining $40 – $160 in goods for 10 minutes worth of work.
Both those guys became multi-millionaires before age 40.
"Shearing sheep and giving away the wool" is an aphorism from my childhood. It was used to describe a poor business decision.
Not the most prestigious job (it’s hot, uncomfortable, and you have to wear a mask), but Google tells me you earn an average of $78.13 per acre burned. So burning 30 acres a day nets $2,343.90.
No, it grosses $2343.90. What do you think your insurance costs on something like that? I'll bet it's non-zero. Simply googling controlled burn cost per acre Iowa blows this out of the water.
I'm sure people in Iowa make money by spending less than they earn.