Currently all theme files like logo, backgrounds, fonts that are theme specific are uploaded to the normal upload folder. Anyone who has access to the files can delete them.
A cleaner solution would be if we could define an “Assets” folder within the theme or child theme via Bricksbuilder, where the files can be uploaded where only a Bricksadmin has access to them.
Something similar has already been proposed for the fonts: Allow Custom Font files to be referenced from Themes folder