In previous versions for over a decade, hitting the backspace key would was a shortcut for the back button. Please reinstate this feature as it no longer has worked in the past several versions of Firefox.
This changed in Firefox 87, and there is a hidden setting to change it back. Check out the detailed steps in my post on the Mozilla Support forum here:
Please, you all in support, give us an option to enable backspace button in firefox. When i surfing on internet, for me it is a much faster to hit backspace button with my hand, when i want to go back page, then to pointed mouse to back arrow. Please enable this option in "about:config". Make it possible for us who need that option. Dont just "cut" for all users, please!!! Whoever does not want to activate this option, will not activate it. So please think about my request.