I have been using Cookie AutoDelete like this for probably more than a year now and it has been working fine as far as I can tell.
Mozilla presumably has a somewhat different opinion, though, otherwise they would have probably added it to the officially supported extension by now. For example, it might drain battery life or something similar, which I wouldn’t be able to tell with my naive usage.
Yes, for the desktop PC there is the addon “Cookie AutoDelete”. Unfortunately, there is no such thing for Android yet.
Well, you can get it installed via a workaround.
You need either Firefox Nightly or an official Firefox build (like Fennec, Mull etc.). And then follow these instructions: https://blog.mozilla.org/addons/2020/09/29/expanded-extension-support-in-firefox-for-android-nightly/
I have been using Cookie AutoDelete like this for probably more than a year now and it has been working fine as far as I can tell.
Mozilla presumably has a somewhat different opinion, though, otherwise they would have probably added it to the officially supported extension by now. For example, it might drain battery life or something similar, which I wouldn’t be able to tell with my naive usage.