It's more like the machinery is incidental to the machine itself - the magic is what makes it works, the inner bits are there because the gods think they're supposed to be, but actually they have no effect on how things work. The parts could be salvaged and used in other things, but their initial purpose is more aesthetic than anything else.

tl;dr: the gods don't know how machines work, everything works via magic, they just put parts inside because they think parts are supposed to be there.