.NET also runs on Android and iOS so Ryujinx could support them in the future. Most emulators written in C/C++ don't run on all of those platforms either.
They appear to distribute Windows, Linux, and macOS builds. I'm not plugged into the .NET/Mono scene, but the download (the Linux one at least) appears to be an AOT-compiled ELF file, with no dynamic dependencies (well, aside from possibly dlopen()ing things at runtime) on .NET/Mono components. I was able to run it without installing the Mono runtime or any libraries.
Where would you be running this where you’re also blocked by net support?