I remember when on line checkin was a "new fangled" idea, and to encourage it BA (for example) had "fast bag drop" desks that were exactly that, and the majority of people still queued to check in.
Now of course, you need to "check in at a kiosk" and then drop your bag at the "bag drop" desks - of which there are now fewer than there were check in desks, so the queues are just as long as before; the "fast" has gone from the sign, and the airline (or agent) employs fewer staff....