Flight crew walk arounds are cursory checks; final absolute checks must be a maintenance function.
Eg: If for any reason a departure is delayed by last minute loading and the loading truck unknowingly punctures or gouges the fuselage, the flight crew cannot be aware of that! Only the final THOROUGH INSPECTION by the maintenance crew can ensure absolutely nothing unacceptable.
Excellent idea.
Now, how are you going to re-employ all those maintenance crew who lost their jobs when flight crew took over that function (for a nominal fee
)?