I think this might be more about perception than anything else.
I've used Firefox since 2006, and Chrome always seemed heavier, laggier and uglier. Maybe it's the snappy iOS-like animation when you scroll to the bottom of the page that makes it seem snappier?
It's not imaginary - for years Firefox drained battery on macbooks really fast. Then there is this pesky issue of randomly freezing whole laptop for a minute or so, usually associated with file uploads or locking screen [1], [2], [3], ... Fixed in one version, then appears again in the next version.
I still used Firefox a lot for various reasons (and still do), but I'm not blind to how it performed.
I've used Firefox since 2006, and Chrome always seemed heavier, laggier and uglier. Maybe it's the snappy iOS-like animation when you scroll to the bottom of the page that makes it seem snappier?