Airlines don’t want you checking bags for at least two reasons: 1) For every bag that’s carry-on is one that a baggage handler doesn’t have to deal with (as we

Airlines don’t want you checking bags for at least two reasons: 1) For every bag that’s carry-on is one that a baggage handler doesn’t have to deal with (as well as reducing risks of losing it and all those logistics), so they can reduce the number of people they need to pay. 2) Unused overhead space is wasted space. They’re spending a huge amount of fuel to transport X cubic feet of space from one place to another. If the overheads are half empty, that’s wasted space. They want all the overhead space to be used so they have more space available in the hold. That extra space in the hold is something they can sell. They can carry tons of FedEx envelopes, Amazon packages, etc. as cargo, and of course they can make more money from that than if they used the space for passengers who already paid for the space in the cabin.