While employed in the industry some years ago, I remember seeing the bag measuring device located at the jetway entry. Many of the carry on bags didn’t fit and were boarded without complying. The result was oversize people trying to fit oversize bags into overhead containers. The struggle ensued and reminded me of a couple of summa wrestlers trying to get the other fellow into the corner.
After numerous decades of observing that pax want more for less, decided the best way to handle this would be to sell tickets based on your total weight boarded. Having a scale next to the ticket counter and the display in big letters might convince some folks to downsize a bit.