I believe I may have a solution which should be relatively easy to implement without a lot of cost.
Simply install locks on the overhead bins. Permit laptops, cameras etc to be brought on board (in modest sized cases) and secure and LOCK them before flight. No extra hold baggage, no lost or stolen irreplaceable items and people will not mind as much having their stuff in sight even if they can't actually get to it. And in the event of an emergency (medical etc) it could be got by a crew member as needed.
Hope someone who matters sees and reads this.