Do note that LW deletes all cookies upon exit. This default setting can be changed of course, but it tripped me up.
Cleaning out all my browser history after every exit really has changed my relationship with the address bar.
Another way of looking at this method is as an antidote to ending up with hundreds of open tabs – I just bookmark it and close it, knowing I'll find it back later when I actually need it :)
On the pages where you want to stay logged in like in HN, click the lock icon left of the URL and toggle "LibreWolf: Always store cookies/data for this site" and that's it.
There's certainly something refreshing about knowing exactly for which sites I'm storing cookies (so far kagi, HN, gmail, YT...)