It’s because of safety standards. 50 pounds isn’t a set limit, but you can see how any decent lawyer can take that NIOSH model used and get a crapton of money from a company if an employee does get hurt lifting more, so conservative companies that don’t want to have to pay out will set that limit themselves.
Of course… What airline companies are most concerned about is the well being of their luggage handlers.
Even if they claim that this is one of the reasons, it’s a by product of cost management.
It’s because of safety standards. 50 pounds isn’t a set limit, but you can see how any decent lawyer can take that NIOSH model used and get a crapton of money from a company if an employee does get hurt lifting more, so conservative companies that don’t want to have to pay out will set that limit themselves.