When speaking to a Chinese student recently he described each Chinese dynasty as being demonstrably different from the previous one- each dynasty formed it's own country as opposed to one country with multiple ruling families over it's history. He specifically compared it to the Byzantine empire in this regard- despite the ruling families in Byzantium changing- it was one country. I know very little about Chinese history and was wondering how accurate his statement was.
Different dynasties in China are formed after rebellions that overthrows the previous government so it would been impossible for any of the old ruling family to remain, they would have been exterminated or at best exiled.
In Byzantine's case, it was largely internal appointment, inheritance or political maneuvering to install the a Emperor rather than an rebellion that overthrew the government. The empire never fell, it was just a changing of rulers.
And in that sense yes, every dynasty most definitely should be viewed on their own