It's that time of the year when we can expect to see Magpie fledlings out & about. Please drive carefully for your & their sake.
I was reading in Gisela Kaplan's Australian Magpie that beaks in wild-raised Magpies are consistently longer than in hand-raised Magpies. This suggest that it's easier for wild-raised Magpies to obtain more & a greater variety of food than their hand-raised counterparts since Magpies feed by sticking their beaks into the ground to obtain detected morsels. In turn, this suggests that it's a good idea not to artificially feed Magpies, at least.
I would also suggest that hand raised magpies do not suffer the normal "wear and tear" to their beaks, which those in the wild would (in line with your suggestion that wild birds have to work harder for a feed).
Dale Huonville, Tasmania