Uh, that's not my experience at all...I use FF normally, and Chrome not uncommonly (sometimes it's handy to have an entirely separate browser, plus compatibility testing), and I find no noticeable difference.
I agree in windows, but in Linux and android FF has some issues. I still use it but sometimes if a page is being super slow I'll open it in chrome instead.
Hmmmm...not denying your experience, but I haven't used Windows routinely in years; my last several laptops have been Linux. Maybe I just use different websites?