Which one is less polished, and are you implying Chrome is more so? Maybe it's "polished" but it's incredibly slow and FF/Brave both have better features from what I can see.
It’s not factually accurate to claim that chrome is “slow”, especially vis-a-vis Firefox.
I’ve found it depends more on which hardware you use than on which browser. Firefox is unusable on some of my machines, where Chrome is OK, and it’s the opposite on others. (All are low end machines.) I think it mostly depends on video drivers.