> in practice, all the complexity of C# building disappears into Visual Studio
> IMO, that's even worse.
To be fair, the more accurate way to phrase it is "disappears into .NET tooling". Because this part is also exposed through standard CLI of .NET, and isn't Visual Studio specific. Managing packages through npm and dotnet is quite similar, with a significant difference that the average dependency graph of a .NET application or a package is 10 to 100 times smaller than the one of Nodejs, and the compatibility breaks happen much, much more rarely.
> It means that when you want to learn C#, you're also forced into learning a complicated tool that isn't really useful for much else.
This is untrue. On top of Visual Studio, your choices are Rider, VS Code and VSCodium, Neovim and Emacs, and anything else that integrates through VSC extension bridges, LSP and debugger adapter protocols.
I also usually recommend to all newcomers to start with CLI to manage projects and packages, because it's more straightforward than navigating through all sorts of windows in an IDE, and because they also get know the basics .NET builds on top of. It's an experience that is very similar to using Cargo.