If we look at .NET vs Java, then yes, Microsoft is better. Microsoft may charge for some of its dev tools (Visual Studio etc), but .NET itself is and was always totally free.
However, above and beyond free, it is also a collection of ECMA standards https://learn.microsoft.com/en-us/dotnet/fundamentals/standa...
Now, don't get me wrong: I have grave suspicions there is currently only one actual implementation of them (I don't count hobby, or abandonware, ones) but IMHO "actual standard" combined with "for real reference implementation" is way better than just reference implementation
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since I'm still within the edit window, the MAUI referenced by the sibling comment is MIT licensed https://github.com/dotnet/maui
https://github.com/dotnet/blazor (Apache 2) is marked an archived, and points to https://github.com/dotnet/aspnetcore (MIT) but command-f blazor on its readme is nothing so :shrug:
If we want to be really pedantic they said ".NET" and not ".NET Framework" or ".NET Core", so basically that what came with .NET 5 and newer.
Great GUI cross-platform GUI toolkit (MAUI), great WASM engine (Blazor).
Upcoming .NET 10 is going to be awesome.
And besides, Linux desktop is a mess. I never learned details on how Wayland / X11 / KDE / Gnome etc. work, which is for what. All I know is that some distros switch from one to another, that one is declared the best, and another the worst, and all of it changes regularly. I'm glad someone in Canonical made the desktop mostly working for me in Ubuntu, although it still lacks a lot compared to Windows.
I think when you need that level of cross platform support to cover Windows, Linux, macOS, maybe mobiles, and you do a serious project, you use Qt.