We open files all the time so anything we can do to make this process quicker has got to be beneficial. Depending on how often you work with files and where they are located will depend on which of these options are likely to be of most benefit. Why not give some of them a go.
The keyboard shortcut CTRL + O take you to the default open pane which is quicker than selecting Open from the File tab.
Pinning files regularly used to the Open menu
If you are using a large number of files the ones you want to get access to week after week can sometimes fall off the bottom of the recently used file list. To keep them at the top you click on the pin symbol that appears when you hover over a file from the open pane. Much easier!
Pinning folders regularly used to the Open menu
Folders can be pinned in the same way as files. From the Open pane click on the folders tab at the top to see recently used folders and pin those you need to the top of the list.
Navigating to the correct drive initially
In O365 a list of One Drives and SharePoint sites can be accessed directly from the Open pane without having to go to browse button first.
Bypassing Backstage View
If you want the keyboard shortcut to navigate directly to open dialogue box, bypassing the backstage view, then the default option can be changed. From the File tab and options, under the save section select Don’t show the backstage when opening and saving files with keyboard shortcuts.
I wonder which one of these will make the biggest difference to you.