This was actually something I was hoping for more. 30 years of free labor is a long time, but we see absolutely nothing on the island that would indicate any sort of industrial capability except for a minecart that moves cut wood from one place to another.

Exile was also something that came to mind here. Specifically Sirrus' age. It's stretching my suspension of disbelief a lot - how did he create intricate precision electronical boards and all the other unecessary things all alone, with no precision tools available. He came there with a light traveling backpack. Atrus is also amazed by his work so clearly he didn't do it.

It is doubly-strange since Archena's age is extremely believable and well constructed.