The Bookmarks bar is virtually never "complete" if you've got lots of bookmarks. It has a "more" double arrow button at the end. I don't find the bookmarks bar to be particularly user friendly for screen reader users. Using the Bookmarks Manager (which you do invoke via CTRL+SHIFT+O) as your main launch page for your bookmarks tends to be much easier. I keep a few of my really commonly used bookmarks at the beginning of the bookmarks bar, but in general I rely either on browsing history or Bookmarks manager when I'm taking a deep dive into sites I use infrequently.
Navigation of the Chrome Bookmarks manager is remarkably similar to File Explorer or any of the Open or Save dialogs where a folder tree is involved, only the folder tree in this case is the various bookmark folders. When you combine that with the search box at the top, you can usually get to any bookmark folder or actual bookmark very, very quickly. Once you have focus on it hitting enter opens it in its own tab or window depending on how you have Chrome configured.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore