Why is airplane boarding always a mob scene?

I agree that it's the overhead carry-ons that cause most of the problems. From 1. people wanting to make sure they get space. 2. People incorrectly placing their luggage taking up more space than needed in a bin.

The solution: Carry-on Valet. Have 3-10 airplane employees (indoor luggage handlers) load the carry-on's to the bin above the seat number the person will be sitting in then leave the plane from the back. (For more speed have people start loading as the bins are filled from front to back)

I think large international flights could be excluded.

The airline would need to only have a few more luggage handlers to do this; as they are already at the gate, just outside, right?