[pcwalton]

Same way it works on the web: Use a broker process that grants access via a file select dialog.

[vetinari]

The point is, that for vscode picking a file is not enough. It would cause lot of fun opening multi-root workspaces you just checked out...

There are many more applications, not just IDEs, where picking a file or folder is not sufficient: for example, apps like Rapid Photo Downloader or Darktable would be significantly crippled.