I believe you hit the nail on the head for what's part of the issue - time frame for a flight to take off. My last flight was delayed because the plane didn't make it to the right spot out to the runway at the right time. Perhaps airlines should have customers who need large devices loaded arrive extra early to give the grounds crew more time to get the chairs, etc, down to the loading area? Even if the plane isn't there, the devices could be lined up and ready to load.
That's a great idea. Except... (you knew there was going to be an "except" LOL)
The airport is a lot like Disney World in the respect that *some* of the folks who are using mobility devices can leave them at the gate, and walk down the Jetway, and on to the plane, and that works ok for them.
Others, like me, have to ride down the Jetway, but can take a few steps into the plane to my seat with assistance from my cane and traveling companion.
And some folks will have to roll all the way down to the aircraft door, and transfer to an aisle chair, and then transfer into their airplane seat.
So it's not a one-size-fits-all scenario.
I do agree that for those folks who *can* turn their devices over, the sooner they can do that, they better. You are absolutely correct - the faster they get those devices down to the tarmac, they more time they have to load them. It then becomes a case of trusting that the extra time that mobility users have "granted" the ground crews - by arriving early and being prepared and allowing them to take our devices as soon as possible - is actually used to carefully load our devices.
A lot of the problems come from delays.
Most often, it's weather related, and once they start, the delays can stack fast.
Those weather related delays roll across each airline's system (because a lot of them use a hub-and-spoke model) and as time passes, a small weather delay from an American Eagle flight in Montana that's headed to Chicago can disrupt other flights at O'Hare... and then those delays start to roll across DFW, and Atlanta, and LAX and LaGuardia, and can even affect international flights. Even airlines who don't use the "hub-and-spoke" model can be affected negatively by weather; one plane doesn't take off on time, so it doesn't arrive at it's next location on time, and then they are still late getting to the third airport... It happens regularly, obviously more so during winter months. And every time an airline "holds" a flight to the last moment to accommodate passengers coming in from another delayed flight... the ripples just get bigger and bigger.
So, that's why at a lot of airports, the Gate Agents typically don't start to really work a flight until the aircraft has started it's approach. And if the GAs start saying things like "Folks, we are tight on time, and will turn this equipment around as fast as we can!" it means that everything in those holds will be scraped out as quickly as possible, and they will start throwing bags and loading cargo the moment they have an empty space in the hold. Catering will be loading up new carts and Ground Services will be fueling and checking potable water, etc. even before the plane is half emptied of incoming passengers. It's a frenzied mess, it's literally orchestrated chaos - and it's not at all like the "old days" when a cleaning crew would board the flight, and wipe down tray tables, and fold blankets, and pick up trash, and we would board a (reasonably) clean aircraft while our luggage was nestled carefully in the belly of the plane. Nowadays cleaning usually only happens wherever the bird overnights. There simply isn't time anymore, because cleaning crews take time, and time is money, and everyone wants to fly everywhere, and they want the cheapest airfare they can get, and so the airlines respond by saving time (and money) everywhere they can.
It all comes down to *time*. And I don't know how to fix that...