Airlines continue to unbundle what's covered by a basic fare.
United Airlines announced this week that it will begin charging for the use of overhead space in its cabins. United is the first major airline to do so. As part of a new pricing tier, United is introducing "Basic Economy" for passengers who purchase the cheapest fares. They'll be allowed only one carry-on that fits under the seat. The fare class also restricts seat assignment until the day of the flight. Passengers who purchase higher class tickets will be allowed to stow carry-ons in the overhead, but will still be charged for checked bags.
Also, "Basic Economy" passengers will still be allowed to purchase overpriced food onboard the aircraft. The new fares take effect in early 2017.