Spacing between icon and text on sidebar is too small in file chooser.
Steps to reproduce the behavior:

In comparison to the sidebar in Files for instance

The spacing between the icon and text in FileChooser is a little too tight. The margin around the breadcrumb is also very small, though I'm not sure if this is a design decision or not.

Depends on https://github.com/elementary/files/pull/1417
and probably also https://github.com/elementary/files/pull/1453
The current Filechooser is basically the Gtk.FileChooser with the pathbar replaced by the Files one. Once the NativeFileChooser portal is implemented then we will be able to provide a completely redesigned FileChooser that will match the FileManager UI.
Most helpful comment
The current Filechooser is basically the Gtk.FileChooser with the pathbar replaced by the Files one. Once the NativeFileChooser portal is implemented then we will be able to provide a completely redesigned FileChooser that will match the FileManager UI.