WebUI is switching from i18n-content and i18n-values to $i18n{} (tracked in issue 677338). Files app and friends use i18n-content and i18n-values too, but can't currently migrate to $i18n{} since it's only supported when serving WebUI. WebUI serving also supports gunzipping resources when serving them, which might be nice for reducing disk usage both for Files app and for other component apps/extensions.