I don't think he was arguing against unification; he was just arguing that in practice, the unification Apple settled upon was one that made macOS worse and thu

I don't think he was arguing against unification; he was just arguing that in practice, the unification Apple settled upon was one that made macOS worse and thus represents their continual disinvestment in the platform (because, as you note, "SwiftUI is not it by any means"). This comes after years of neglect for the Mac platform; OP says Apple was "distracted" by iOS, but IMO that is unfair; instead I would say they were focused on iOS, probably correctly, but with a downside cost for Mac users. Macs are no longer the primary breadwinners for Apple, so they get a smaller percentage of focus and resourcing. It sure seems like they could've done a better job at the unification attempts though, at least from the videos of the new Settings app floating around the internet. How can you break toggles that badly? It seems like it should be very hard to make a toggle button that occupies the regular amount of screen real estate, but has a click target that is 1px. That shouldn't happen by accident!