Snow Crash in particular uses the metaverse mostly as an excuse to include sword fights and motorcycle/monorail chase scenes. Fantastically fun in my opinion! But that motivates all kinds of choices (making the Internet a literal place with a street grid and real estate, where people can get chopped up by swords) that real XR tech has no particular technical use for. And I would implore any engineers using Snow Crash as an inspiration to consider how absurd it would be to take all the world's most sophisticated technology and dedicate it to gratifying personal power fantasies. It starts with the almost pornographic display of advanced weaponry and logistics deployed to deliver a pizza, and just gets more gloriously ridiculous from there. The main character is named "Hero Protagonist". The main antagonist has a nuke strapped to his motorcycle. Take a hint!
Anyway, I am happy Diamond Age gets a call-out because it is by far my favorite of Stephenson's novels. And I think the Young Ladies Illustrated Primer is one of the all-time most interesting technological plot contrivances (the Imago machine, game/civilization of Azad, and Shrike all providing strong competition). But the technical constraints/capabilities of the Primer have almost nothing to do with realistic limitations/advantages of AI technology, and everything to do with getting the right characters into the right places at the right times. We need a Miranda to provide the Primer's voice so that Nell can have some kind of human connection in the end, and we need Miranda to be paid anonymously so that Nell won't get that human connection too soon. The Primer is a language model not a robot so that Nell will have to solve problems on her own. Yet she can learn Kung Fu from a language model because we need a few action scenes. I think really the interesting question posed is "Can a person grow up to be influential given no resources except a perfect education?" not so much "Can a language model provide a perfect education?". Many characters in Diamond Age seem to agree with the former notion, but in the end it (SPOILER) gets shot down when Nell needs control of an literal army to come out on top.