True. I think sourcekit-lsp can support iOS projects.
I was trying to make SDE of vscode work on UIKit.
The readme says it will work on UIKit, but it doesn't.
After a little bit of searching, I found SDE doesn't use the arguments from .vscode/settings.json.
Instead, it reads the arguments directly from .build/debug.yaml, which is generated by swift build
If I could apply build arguments for swift build, I can make SDE works on UIKit.