How did Japan avoid a change in dynasty in the past 2000 years?

The Yamato dynasty has been reigning for over 2000 years. The emperors were seen as religious leaders and not leaders. They have only been seen as mere figureheads since World War II. They were powerless because all real power was held by regents or shoguns. Even in the political world, the emperor does not have any political power.

The Yamamoto dynasty are believed to be descendants of the sun goddess Amaterasu Omikami. The people of Japan only refer to the emperor during religious ceremonies. The people do not see a reason to unseat a powerless leader.

The Yamato dynasty in Japan claims to be descendants of the sun goddess Amaterasu Omikami. The reason Japan was able to avoid a change in the Yamato dynasty for the past 2,000 years is because the various Emperors of Japan, for a large part of history, had virtually no power, In essence the Emperors were really just figure heads and were seen more as religious leaders.

The Japanese people depended on the Emperor for religious, ceremonial, and symbolic functions but not governing functions. So, what reason would someone have to make a change if as a result they are not rewarded with power?