They did when switching away from .NET Framework, but this was because they had to reimplement many features from scratch to work on other platforms, and certain parts got left behind.
I've worked in .NET shops with very niche WPF/WinForms applications where customers were years behind with our software/major .NET Framework releases.
I don't think it's a technical challenge, more a cultural one.
They may still get left behind on an older version of your software because they want to be, but their relationship to Windows is no longer the big excuse/reason to skip updating to your latest that it used to be.
Similar feat with .NET core usually results in a 70-80MB executable.
Also if you use trim unused code and compress the executable in my experience it's usually a lot smaller than this.
Now I have to update software and all its dependencies without a real benefit.
It’s equivalent of buying a new PC because MS tries to force Windows 11.
Lets waste lots of time and resources for nothing.
There's a lot of quality of life features of the later versions of C# that we're missing out on. My code was a LOT more streamlined in my .NET 9 app.