I'm not a webdev so I mostly don't care as long as it's FOSS, but I will say that firefox loads a lot faster than chromium on my machine. Looking at top it appears that somehow firefox is actually using more memory than chromium is (i only tested a three tabs open in each browser so maybe they don't scale the same under heavier load) but at the same time I can report anecdotally that in addition to being slower, chromium also causes my HDD to make way more noise than firefox ever does.
Weird cause I have the opposite effect. Firefox is way slower... On Linux, Firefox didn't even implement any video accelerated decoding for the longest time and it is still buggy and has poor support for Wayland with glitchy artifacts during resizing, etc. I'm using an older computer with Linux and wouldn't be able to use the web reliably if it weren't for Chromium.
