[There is a lot there for Athrun to process. Summoned? An era before robotics? As he has no knowledge of magic or Servants, he cannot understand most of it. But, at least he comes from some version of Earth, so...that's something, maybe?]

That's a good point. Progress, or breakthroughs, are often made in order to fulfill a need, or a desire. But if they're using robots for service, there could be any number of reasons why they started doing so. It could be that there simply isn't enough supply of labor to meet the demand.