Themeability doesn't rule out consistency. As long as all UIs use the system theme, they look consistent, no matter what that theme is. A good example of that was Windows XP and all the funny and atrocious themes you could put on it with WindowBlinds.
> Themeability doesn't rule out consistency. As long as all UIs use the system theme, they look consistent, no matter what that theme is.
Agreed. That's why the GUI toolkit must provide as exhaustive as possible a set of widgets, and those widgets must be versatile; so that applications developers can build basically everything from those widgets and not feel the need to build their own from a raw canvas or something like that.
Having just one widely used GUI toolkit would also help, something both Linux and Windows are struggling with (Windows especially, with Win32-style WPF vs Fluent-style UWP)
Also on Windows you’ve got WinForms and MFC and I think another C++ UI framework as well. Microsoft has switched their preferred UI framework every five years or so, often leaving behind the old framework in the dust when it comes to new UI paradigms they want people to adopt. So you’re kind of forced to roll your own if you’re stuck on a legacy framework but want your app to look modern. It’s a mess. Now they’re just starting to roll out a new one called “WinUI”. I’ll wait a few years before deciding if it’s worth the effort to learn or if it’s just another one for the scrapheap.
That's the root problem, though, isn't it? It's a business/people problem. You won't have consistent UIs as long as software vendors consider look&feel as something to exploit for branding or competitive advantage. Since user feedback is rarely sought and routinely ignored in computing, you'd need the OS vendor to either disallow UIs not conforming to system theme, or make them impossible (by taking away the API for per-pixel drawing). Neither of those options is likely to happen.
Back in the XP days, there were generally two kinds of UIs: the ones that used the system theme, sometimes as much as trying their best to apply it to their custom controls, and the ones that disregarded the system appearance altogether and drew everything themselves, including the window borders.
> Since user feedback is rarely sought and routinely ignored in computing
This needs to change, too. I collect user feedback and act on it and my users love me more often than not. The world would be a better place if everyone was doing this.
