You know what eats up RAM? Having auto-playing videos, translucent overlays and Javascript.
Techradar takes 65MiB of RAM to display, including ad blocking by pi-hole and several add-ons. Hacker News takes a bit more than four. Sure, Firefox will eat less RAM, but with sites like these, any browser will eat RAM like crazy.
Want to stop browsers from eating RAM? Make better websites. No news website should require 6MiB of RAM just to store Javascript.
Most modern websites end up allocating an absurd amount of RAM. Although there are certainly some that are more lightweight.
I have found that Firefox uses less RAM than Chrome for my workloads. That being said, if you have limited RAM, the amount used by either is still extremely high. I suggest installing Auto Tab Discard [1] for Firefox or The Great Suspender [2] for Chrome. These will allow you to discard tabs and reload them later without closing them. Please do note that any state on the page, aside from scroll position, will be lost. This usually includes text entered into complicated forms.
I would switch to Firefox if they managed to support the basically unlimited amount of tabs I can open on Chrome without any slowdown or degradation.
There's probably a better way to manage it, but when you're going down the rabbit hole of stackexchange and Google to try and figure something out, it's an extremely invaluable tool for me personally.
I always have 7 Firefox windows open across 4 virtual desktops with over 100 tabs across them. Never crashes on Linux and never eats all my 16 GB of RAM. Right now it's using about 4 GB of RAM. When I run Chromium in 1 window with 4 tabs, within hours it's using all available RAM and the tabs start crashing, one at a time, as they fail to allocate more RAM.
https://news.ycombinator.com/item?id=20856836