It’s still mainly just a text editor and not “full-blown”. There is no significant built-in user interface, gui designer/builders, or emulators for example. The plugins can be native, which could allow for this. Essentially, vscode is a text editor that allows for native plugins, which explains the high performance possible.
Emulators are not native to IDEs, there's always glue code, you can write a plugin for it. I don't know about GUI-Builders, but in principle you can do anything. It's just a web view after all. Vscode is incredibly flexible. I have written a paper with it including live preview of the pdf. But I don't care about GUI-Builders. You only need them for apps and then you are stuck with each walled garden anyway and forced to use e.g. Xcode. Except ios/android apps, who's native anyway in the 21st century? ;)