In my groups we've interpreted it like this:
* a lot of these fantastic machines are still controlled by basic computation power - like the hardware and software used for the moon landing. This explains why a kid can roll for tinker to control a machine, or calculate to get how it's built.
* fantastic machines and advanced tech is expensive and partly government controlled. This explains why it's not available for everyone. A really wealthy farmer might have a magnetrine tractor, and well-off inventor might have electronics for simple AI. Essentially, the kids get the "low grade stuff" and the grown-ups don't want them to use the advanced stuff yet (a bit like cellphones and computers today).
* the advanced tech is partially known, but unobtainable, unless someone's parent or something is using top level (secret) tech at home. and a lot of the tech found in mysteries are top secret military or government property. Kinda like: you cannot buy or even fly a fighter Jet, but you can see it fly by and be amazed.
It is a bit of a conandrum though.