In the same way that a car is faster if you make it lighter by removing parts that aren't technically needed to drive down the road :) Airbags, ABS, Crossmembers? Meh.

How much faster does it need to be? I have some complaints about FF, but not on the account of speed. I don't care about microbenchmarks, for me it works fast enough to not notice any lag.

Besides, I really don't care how fast it it when displaying ads and tracking me. I'd prefer not to see them, thank you very much.