I'm interested how differences with robots work overtime, there are a lot of machines in this world that have been patched or "jimmied up" to continue working, let's say a mining robot, it would probably get quite heavily contaminated with dust, wear would occur in different places, rock falls might bend parts.
So even though another robot could probably do the "jimmy up". it seems like overtime, the robots will "drift" into all being a bit different.
Even commercial airlines seem to go through fairly unique repairs from things like collisions with objects, tail strikes etc.
Maybe it's just easier to recycle robots?