Microsoft hasn't really dogfooded their own external facing GUI frameworks in forever. It's not a great look, but to some degree it also made sense. These frameworks (especially the dumpster fire ones) are .NET/C# (usually with XAML) frameworks, designed (it feels like) primarily to build line of business internal applications, with cross-platformness tacked on in more recent years. The grand-daddy of all of these would be WPF (all the way back in 2006).
Basically Microsoft's flagship non-developer apps (ie Office Suite) is its own little kingdom. They never bought into any of the developer facing C# frameworks that MS created (makes sense I guess?... Office isn't a C# code base). Office basically developed its own visual language and internal framework.
Visual Studio itself actually got some WPF back in the day (though I understood the code base to be kind of what you expect of something of its heritage). I imagine it still has WPF to this day.
Their newer apps - especially the ones that are actually trying to be cross platform (like Teams, VSCode and friends). Well, Teams has the excuse that they need a web version anyways, so Electron really does make sense (see Discord and Slack).
VSCode... the first version of VSCode came out in 2015 (omg..... it actually released a few months before Windows 10). MS had no in-house cross platform solution at that time. At that time, they did have a partnership with Xamarin (Xamarin would later be acquisition). .NET MAUI is the evolution of Xamarin. But Xamarin I always understood to be a bit of a dumpster fire. I was evaluating our choices for a small windows desktop app back in ~2015-2016. Xamarin did not seem appealing. After a misfire with UWP (another MS footgun I think), we just did WPF (cross-platform not required).
Honestly, I wouldn't expect anything that could even remotely be described as an "IDE" to NOT be based on the VSCode code base now. MS has something -very- good going for it there.
And I guess this is kind of one of the challenges. The part of MS that builds apps, is not really related to the part of the MS that builds GUI frameworks for external developers. And the part of the MS that builds apps does not really want their success to be tied to this dumpster fire.
Basically Microsoft's flagship non-developer apps (ie Office Suite) is its own little kingdom. They never bought into any of the developer facing C# frameworks that MS created (makes sense I guess?... Office isn't a C# code base). Office basically developed its own visual language and internal framework.
Visual Studio itself actually got some WPF back in the day (though I understood the code base to be kind of what you expect of something of its heritage). I imagine it still has WPF to this day.
Their newer apps - especially the ones that are actually trying to be cross platform (like Teams, VSCode and friends). Well, Teams has the excuse that they need a web version anyways, so Electron really does make sense (see Discord and Slack).
VSCode... the first version of VSCode came out in 2015 (omg..... it actually released a few months before Windows 10). MS had no in-house cross platform solution at that time. At that time, they did have a partnership with Xamarin (Xamarin would later be acquisition). .NET MAUI is the evolution of Xamarin. But Xamarin I always understood to be a bit of a dumpster fire. I was evaluating our choices for a small windows desktop app back in ~2015-2016. Xamarin did not seem appealing. After a misfire with UWP (another MS footgun I think), we just did WPF (cross-platform not required).
Honestly, I wouldn't expect anything that could even remotely be described as an "IDE" to NOT be based on the VSCode code base now. MS has something -very- good going for it there.
And I guess this is kind of one of the challenges. The part of MS that builds apps, is not really related to the part of the MS that builds GUI frameworks for external developers. And the part of the MS that builds apps does not really want their success to be tied to this dumpster fire.