Firefox 57 with Photon UI allows to access all stuff – Bookmarks, Pocket List, History, Downloads, Synced tabs and Screenshots – from one place, that is from the Library menu.

Firefox 57 : Recent Bookmarks and Pocket List removed from Bookmarks menu

Since Library menu already contains Recent bookmarks (in the submenu of Bookmarks) and View Pocket List. Mozilla has removed these from Bookmarks Menu button, which won’t be on the toolbar unless you drag and drop it from customize window, same the case with Search bar and other items.

So Firefox 56 is the last version with Australis design to show recent bookmarks and Pocket list in the Bookmarks menu, Mozilla changes Firefox UI to Photon in version 57, which set to release on November 14, 2017.