In plato's republic the benevolent dictators choose their successors to also be benevolent dictators, do not know if that could work in real life but the CCP do chose their successors, and not based on blood lines
And Xi has consolidated power and purged all competent up-and-coming potential successors that threaten this power. He shepherded through a modification in Chinese law to allow him to serve for life. Previously, the vaunted governing expertise inside the CCP had an age cap for its leaders. Not inspiring much confidence in their system.
Another thing that doesn't inspire much confidence is looking at Hong Kong. The people there have unambiguously and collectively spoken about their desire to live under this system, often at grave personal risk.
Xi has only served for around 7 years, not even as long as some presidents. Merkel has served for somewhere around 15 years and many senators and congressmen have served for multiple decades.
AFAIK during Plato's life no more than about 40 thousands citizen lived in Athens (along with up to ~3 times more non-citizens). Plato's Republic was about politics in such a city-state, never about a bigger human group (for example one of our current huge nations).
AFAIK during the height of Athenian democracy there were no more than 50k ish male citizens that lived in Athens, and all of the same ethnic group. Democracy only works for politics in such a city-state, never about about a bigger and more diverse non male group (for example one of our current huge nations)
https://in.news.yahoo.com/xi-jinping-undertakes-fresh-round-...
Another thing that doesn't inspire much confidence is looking at Hong Kong. The people there have unambiguously and collectively spoken about their desire to live under this system, often at grave personal risk.