Wow, you are really confused. The argument about the functionality being already implemented by Firefox was about https everywhere. This has nothing to do with adblocking and it does break some sites (the one still not using https) but you can still access them with a click.
Privacy Badger stopped using heuristic 4 years ago because it could be used to fingerprint you.
Cookie autodelete simply does not work with Firefox’s Total Cookie Protection, which is enabled by default.
https://addons.mozilla.org/fr/firefox/addon/cookie-autodelete/
You don’t even need an extension to automatically delete cookies, just enable
privacy.sanitize.sanitizeOnShutdown
andprivacy.clearOnShutdown_v2.cookiesAndStorage
. To add an exception: Ctrl+I>Permissions>Cookies>Allow.Check Arkenfox’s extension page and the section about sanitizing on shutdown.