You're applying costs in a real world to costs in an imaginary one, why would no other tech improve in this hypothetical universe? Anywhoodles you can see a case for governments providing older recycled units to the poor and elderly for general caretaking as a safety net. Its not unreasonable to see them, in a society that has advanced to the point they can make these robots at scale that work well, cheap and is widely available at the lower end of quality.