A ton of speedup in the bag checking process could be obtained by upgrading the kiosks for a snappier and simpler UI/UX.

-Swipe credit or frequent flyer card

[WAIT]

-Enter the airport identifier you are going to

[WAIT WHILE I PULL OUT MY PHONE TO LOOK UP AIRPORT IDENTIFIER]

[WAIT WHILE COMPUTER THINKS ON THIS]

-Is this your flight?

[WAIT]

-Do you want to choose seats?

[If you haven't done this online, hoo boy are you in for five minutes of frustration]

-Do you want to check bags?

[WAIT]

-Are you active duty military?

[WAIT]

-Can you confirm that you have removed all lithium-ion batteries from your checked luggage?

[WAIT]

-Federal law prohibits the following long list of dangerous items. Can you confirm that you have none of these?

[WAIT]

-How many bags do you want to check?

[WAIT]

[God help you if you have a nonstandard item here, eg skis+boots, which the airline will only charge you for one bag for, but will require two baggage tickets]

-Printing your bag tags.

[VERY LONG WAIT]

[20% CHANCE THE PRINTER SHITS THE BED]

-Please affix the tags to your bags in a way that makes perfect sense only if you do this frequently

[NON-FREQUENT FLYERS ADD 5 MINUTES TRYING TO FIGURE OUT HOW TO AFFIX THE TAG TO THE LUGGAGE]

[LONG WAIT TO HAND BAG TO EMPLOYEE]

Employee: You did it wrong, do it again.

I fly United a lot, maybe people on other airlines have more hope