Nice list. Some thoughts:
- I think without the move to NeXT, even if Jobs had come back to Apple, they would never have been able to get to the iPhone. iOS was - and still is - a unix-like OS, using unix-like philosophy, and I think that philosophy allowed them to build something game-changing compared to the SOTA in mobile OS technology at the time. So much so, Android follows suit. It doesn't have a command line, and installation is fine, so I'm not sure your line of reasoning holds strongly. One thing I think you might be hinting at though that is a missed trick: macOS today could learn a little from the way iOS and iPadOS is forced to do things and centralise configuration in a single place.
- I think transaction processing operating systems have been reinvented today as "serverless". The load/execute/quit cycle you describe is how you build in AWS Lambdas, GCP Cloud Run Functions or Azure Functions.
- Most of your other ideas (with an exception, see below), died either because of people trying to grab money rather than build cool tech, and arguably the free market decided to vote with its feet - I do wonder when we might next get a major change in hardware architectures again though, it does feel like we've now got "x86" and "ARM" and that's that for the next generation.
- XHTML died because it was too hard for people to get stuff done. The forgiving nature of the HTML specs is a feature, not a bug. We shouldn't expect people to be experts at reading specs to publish on the web, nor should it need special software that gatekeeps the web. It needs to be scrappy, and messy and evolutionary, because it is a technology that serves people - we don't want people to serve the technology.