As usual with any airline that's not Southwest, boarding is a pain. People rush the line, desperate not to be the last on the plane and have to search for overhead space that might not be near their seat. That is, that's how it used to be.
Moving from inconvenience to outright abuse, American Air has started "gate checking" your carry-on baggage if you're boarding near the back of the plane (group 7 and up). Assuming they have competent engineers, there should be plenty of room for everyone's carry-ons even without their new practice of asking everyone to put their "personal item" under the seat in front of them. There's no excuse for American to not have plenty of overhead room for every passenger… but it gets worse.
The bags taken during the boarding process aren't guaranteed to be there when you land. They didn't lose them between the walkway and the tarmac, they deliberately separated them to go on a later flight. How do I know? Because the "lost luggage" counter where a full staff of 5 employees was ready and waiting told me so just before they handed me the "sorry, not sorry" toiletries bag (nicely embossed with the American logo).
It's pretty easy to put the pieces together. There's no legroom, there's no baggage room, and they won't even put the bags in the hold of the plane that was already there and had the baggage door open and waiting. This is about maximizing people on each flight and spreading the luggage weight around. Or, put simply, profit before service. Of course, I got my bag the next day because their contract-delivery service (which I imagine is busy every day), delivered it as promised, but that's no excuse for getting it right in the first place.
Besides my own two instances of issues, the other attendees of my business trip reported late luggage and cancelled flights; always on American. I will definitely be looking to fly with someone who doesn't play stupid games with passengers.