This is exactly the opposite of what I experience; Chrome eats up 6GB of memory with a couple dozen tabs open, but I can have as many and more active in Firefox

This is exactly the opposite of what I experience; Chrome eats up 6GB of memory with a couple dozen tabs open, but I can have as many and more active in Firefox on 2GB (and over 1000 tabs open but inactive – leftovers from when tab groups were removed… that was a shame). Firefox just also feels faster in general. I am using the developer edition instead of stable, though, and there have been a lot of somewhat recent improvements; maybe that accounts for the difference.