Comment by somenameforme

The ability to physically move fast has relatively little role in bullet beyond a certain level, because most games will end on the board instead of in a frantic mouse scramble. This was even tested, to some degree, in one of chess.com speed chess championships. They had a bunch of top players including Alireza and Nakamura play one of the little reflex games where you have to click in a certain spot that lights up, and their performance was nothing noteworthy. Nakamura, the oldest player by far, was actually the fastest but his reflexes were again nothing spectacular, so it was more of a reflection of the reflexes of the other players.