Comment by MSFT_Edging

The thing that bothered me is it didn't always happen, at one point there was performance parity, and things changed in a way that specifically worked worse in firefox.

Which means:

A) Firefox had bad webgl implementations(I didn't experience what you did, but I wont say it doesn't happen) and google added features that regressed the experience on other browsers.

B) Google knowingly made performance worse on Firefox, regardless of webgl implementations.

C) Google leverages its own browser to only test on their browser, to influence the market to have to use googles browser in order to use their services(not the same as the IE/Windows monopoly lawsuit, but sure smells like it).