Never been to a house in IL that didn't have a basement so that's odd. Guess those are the houses only stupid people buy, therefore I would never have seen it.
When we were looking for single family houses online, saw many that didn't have a basement. Seems to be more prevalent in 60's and 70's construction. My subdivision, which was mostly built in the early 70s, has a mix of basements no basements. Some models don't have any part of the house below grade.
That said, I would agree with you prior to that. Growing up, all my friends had basements no matter the house size or age of the house.
Now, the only friends of mine without basements are ones who live own townhouses or duplexes.