My dentist when I was a teenager didn't believe in extractions as long as those teeth were coming in OK. So I didn't get the first one removed till I was already into my 40s. Eventually all four had to come out; apparently with aging there's some bone loss at the rear edges of the jaws.
Before I got my braces about 45 years ago, my orthodontist told my parents that I needed to have 4 of my regular teeth removed (one in each corner) to make room as the teeth were crowded.
I don't know how much money was made on that decision (which would have been made by a different dentist anyway, so the orthodontist wasn't making a decision for personal gain). I suspect not all that much money back then given my braces were much cheaper than they are these days as well. I tend to think that our orthodontist probably made the right call.
Was using an expander even an option back then? I've never heard of this. Although extractions aren't fun, they aren't long lasting. Expansion of the palate sounds absolutely excruciating and long lasting.