Well there are guys that pull up to a power line and hook on and pull a length of wire out of the conduit or off the power pool. That is more of an “industrial” operation. BTW they strip the insulation off before selling it to a scrapper. Average low end thieves don’t operate that way. The wire from a house is small potatoes in the bigger picture. Copper pipe is used less and less in new construction.
And let's not forget copper plumbing fixtures...bathroom,kitchen,heating system.