Firefox isn't with useful tool, which is tabs suspender, it saves of much hardware consume and doesn't allow your PC stay slowness and/or your own internet, because tabs can consume internet and recourses in background without you use it, so that's important and should be in all popular browsers including Firefox. I recommend they base on auto tab discard and possibly performance tool (by Microsoft Edge), because auto tab discard extension is really complete and very useful, mainly it saves where you stop on certain time video and performance tool saves much your recourses on your computer and is very efficient:
Allow suspend and/or offline a specific tab
It would be helpful to potentially free up resources by allowing someone to suspend processes associated with a specific tab or even offline that tab.
(Note: similar ideas have been merged into this thread)
It would be awesome if the Firefox browser also has the feature "Sleeping Tag" as that in Microsoft Edge, which is extremely desirable for me when using Firefox to open and keep a large number of browsing tags. "With sleeping tabs in Microsoft Edge, inactive tabs go to sleep after the amount of time you choose, freeing up CPU and memory to help make your PC faster." I hope the Firefox team considers developing this for the next release. Thanks!