While the 1978 Airline Deregulation Act succeeded in lowering average fares, it led to several negative structural shifts in aviation. One of the most significant was the loss of direct service to small and mid-sized communities; as airlines focused on high-profit "hub-and-spoke" models, many smaller cities saw their major carrier service replaced by more expensive regional turboprops or cancelled entirely. This era also saw the collapse of legendary carriers like Pan Am, TWA, and Eastern Airlines, who could not survive the "cutthroat" price wars. From a passenger perspective, deregulation ushered in "unbundling," leading to the rise of ancillary fees for bags, seats, and food. Furthermore, the intense pressure to reduce costs resulted in narrower seating and less legroom to maximize "load factors." Finally, it triggered massive industry consolidation, leaving the U.S. market dominated by just four major airlines, which some critics argue has reduced true competition and led to price spikes in "fortress hubs."