All those standards are good examples of write once, debug everywhere, implement multiple code paths tailored by bugs, OEM specific features and workarounds.
Making the end result in industrial code bases hardly much different from implementing multiple times.
I’m one of the most vehement proponents for the use of platform-specific UI toolkits here, but even I disagree with that this statement without qualification. Standards, in general, are a useful thing to have. We’ve occasionally seen (for example, in the case of application frameworks) that each platform doing their own thing has now made it so that the better experience for the user is the non-general API. But standardized interfaces (POSIX, OpenGL, JavaScript) when done right have been a boon for developers and end-users alike.