There are few games which have done weapon degradation well, Dark Cloud is my favourite example of it, it had weapon degradation, but you had ways to repair it in the field and it wasn't expensive to do, weapon degradation speed depended on the enemy you were fighting, your weapons endurance level and whether you had any monster killer things added (different ones for different types).
I think it's wholly dependant on the game and how they implement it in said game
I think it's wholly dependant on the game and how they implement it in said game