It needs a fix even as a sidebar. It is a nuisance to click Admin in the sidebar to have the sidebar retract and then you have to click the 3 bars to re open the sidebar for the admin panel
Recommend to reduce clicks to have it swap from regular side panel to admin panel upon clicking admin in the standard panel.
Since admins are rare users. I would move Admin to Top of sidebar as a Toggle switch that opens the Admin side panel after closing the standard sidebar.
Keep the functionality of what it was save it opens the sidebar vs the top menu. Also keep the fall back accessible under all settings. As all settings is just the settings drop down and not all settings as described.