[coldtea]

>I'd say, for personal devices, folks expect a shiny new UI every OS update.

A 99% of folks could not care less, when they're not downright annoyed by the UI changes. There has been major reactions on UI changes (from Office, Gmail Windows, Gnome, iOS and macOS to Facebook). There have been in comparison crickets about the UI not "updating fast enough", and those are mostly from designer types (like the stupid "skeuomorphic" hoopla a decade ago).

A small minority of designers and superficial people is the one making any noise about UI needing to be updated every time.