Why did the capital of Byzantium remain in one place, and the capital of the Caliphate moved more than once?

Constantinople, due to its ideal geographical position at the intersection of trade routes, became the center of the formation of a new people – the Romans. On the contrary, the caliphate united several different peoples, who consistently played a leading role in the power. That is why the capital moved from Arab Mecca to Syrian Damascus, then to Persian Baghdad, Berber Cairo, Gothic Cordoba.