Indeed, you're caught between the herd-followers and the people who know enough to know the carry-on space might be gone. I don't see many cases where it's gone by the time people get on the flight if they get on when the row number is called, but standbys and latecomers are often out of luck. This assumes, too, that there's some semblance of enforcement of carry-on limits at some level, even if not to the letter.

Would also say that U.S. domestic flights are generally in better shape than ones in places like southeast Asia. There, some LCCs make people line up for open seating a bit like Hawaiian Airlines does in the U.S. It's a worse version of the oft-heard complaint about Southwest.

Also, transpac flights out of Asia often get "gate lice" because of language barriers, general confusion or poor handling. Even otherwise fine carriers like SQ can often drop the ball in that area.

Too, you've sometimes got flights out of hubs (like MSP) with "too many elites" to call an elite boarding. Sometimes in those cases they'll call platinums and golds only and make the silvers board with everyone else.