You're forgetting the actual heavy lifting that proper IDEs do, and that VS Code leaves to language implementors. Unless you know how to do proper code analysis

You're forgetting the actual heavy lifting that proper IDEs do, and that VS Code leaves to language implementors. Unless you know how to do proper code analysis, you won't be able to make it "just the way you like". Even writing a proper IDE-aware compiler is a quite a daunting task.