This is what I'm saying! At the risk of ad hominum - I feel like a lot of the comments classifying VSCode as merely a text editor haven't really used it for development - at least not directly or in a long time.

Though this whole thread could really be considered off-topic since the original post is about Visual Studio for Mac!

Does it or are they available as a plugin?

Yes. These features are directly supported by VSCode. They aren't added via plugins.

Support for specific languages/debuggers/build systems is provided by extensions.

Look up how LSP and DAP work for example. A hugely successful extensible IDE system.