The reality of the "lack of competition" false premise is that air fares in the US are, on average, cheaper today than they were in 1984, at the time of the enactment of the ADA, when adjusted for cost-of-living / inflation. Doesn't mean that there aren't some occasional outliers. But, it does mean that the number of carriers is a red herring.
If there were a market for four-class widebody service with suites for F on the micro-hop from NYC-CHI, someone would offer it. But, there is not, so it's not offered. Instead, consumers choose cheaper fares with a lousier soft product.