To be fair, your browser probably has a history menu option in the top menu that opens a sidebar with your recent history. You can probably right click the top page and click “open in a new tab”. This is highly discoverable and does the same thing (just in more steps). You can also select the text in your URL bar, right click and copy, then open a new tab the usual way and paste the URL there. Also the same results but highly discoverable with extra steps.

As far as I know highly discoverable means there is no hidden functionality, not that every shortcut is advertised.