I know it is completely insane, but I have a strong compulsion to keep my tab count low. Once it starts approaching 7 or so, it is time to evaluated which 3 or 4 have to go.
Meanwhile I go look at someone else's monitor and they have 25 open all the time, and I can recognize some haven't been touched in weeks. I just think to myself "Clean up after yourself. How can you live like this?"
I also don't see how people have the RAM to have 50 tabs open. If I can't read part of the title of my tab, it's being moved to a new window or closed.
In a single processed browser, ram is not an issue. I've been using 25+ tabs for many years, only recently in Chrome I experienced a low ram warning (i have 8GB). I switched back to firefox 56.
Since I got a 32 GiB RAM computer, I don't know what is the memory usage of Firefox anymore.