In the mini-guide above they already moved the SDK ("Software Development Kit") across the air-gap, yet creating a hello world still requires downloading even more stuff, because the .NET SDK does not actually contain enough stuff to create hello worlds, apparently?
Contrast this with e.g. Zig for Windows is a ~60 MB zip file which contains the entire Zig/C/C++ compiler with cross-compilation support for basically everything, and also has complete Win32 headers + libraries in it. There's even DDK headers in there, though I'd expect to do some legwork to build drivers for NT with Zig.
If you're happy to sacrifice the benefits of .net and spend time writing basic Win32 apps, that's totally a choice you can make. Or even just use .net framework 4.6 and not add any extra dependencies.
I'm not really sure what you're complaining about here. .net core is split into tiny packages - if that is hard to handle in your very special environment, you get to use special solutions to make it work.
That's besides the point I was making, which is that there's runtimes/languages which lean towards "internet required for development" or even "internet required for building" while there are also languages/runtimes which are self-contained and independent.
That being said, WinForms is also "just" a Win32 wrapper, I don't see a compelling reason why a similar wrapper wouldn't be possible in pretty much any language. .NET 4.6 is a fine choice too, especially because you're not forced to ship runtime and standard library, as Windows already has both.
I believe that's very much related. The more of the nice wrappers you provide, the more you have to decide if someone needs them all or are you providing them on demand. With .net core doing more splitting than framework and with Java going through a decade of jigsaw, I think we collectively decided we don't want to include everything upfront.
We don't even require the internet for building/development. In .net land you require internet to get the dependency you're using the first time. If you want to get them all and distribute/install before you start development, you can totally do that. It's just not the default behaviour.
It's gonna blow your mind when you realize that `dotnet publish` produces an artifact that IS machine-independent, and that you would just distribute that. Or if it somehow really bothers you, put it in a self-extracting ZIP or MSI, wow, so much better. And I don't know what golden age of the Internet you grew up on, but there's always been "apps" distributed as zips, or as more than just a single binary.
I get that you have opinions, but you seem to have entirely missed that the runtime is downloaded at build time and included in the bundle. And god forbid if you like doing everything by hand, you don't have to use Nuget and you can manage every last dep by hand, however you like (and you'll likely end up hacking something that is less usable than just setting up a private nuget server, but "opinions").