Same goes for any visa.
To get a J1 I had to deliver quite a few documents and go the local US embassy to do an interview there.
An ESTA you can do literally 10 minutes before checking in (I did it once), I doubt anything else than a few basic automatic checks are done.
I assume he's lost the price of the flight? Travel insurance wouldn't repay it?
If you're looking for better, you need to find a job to sponsor you and you need to go through the lottery (H1B). Or you need to work for a US company abroad for more than a year (L1). Or you need to get married with an american person.
But those are more of a hassle compare to ESTA. Nobody from an ESTA country will do those if they're not immediately denied.
Nope.
https://travel.state.gov/content/visas/en/visit/visitor.html
You fill out a DS-160 and go through the process, but you don't have to get an ESTA. You are always allowed to apply for a full visa instead.
More succinctly, click the "May I apply for a visa instead of using the VWP?" question on this page: https://travel.state.gov/content/visas/en/visit/visa-waiver-...
Notably, the Customs and Border Patrol officer at your point of entry can do this [1], on the spot.
[1] https://esta.cbp.dhs.gov/esta/application.html?execution=e1s...