Why is Google terrible on Firefox Mobile?

Mobile Firefox has been out on Android for a while, and in my opinion it's not very good. The UI looks very amateur-ish for one and the other major problem I have is that Google's mobile website is terrible in this browser. I'm guessing this has something to do with it not being a webkit browser but I really don't know. So I'm asking you guys, why is Google so terrible on Mobile Firefox?

Firefox

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Chrome

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