I agree, there seems to be a cycle between democracy and tyranny. However, I think hereditary monarchies are on their way out (with notable exceptions).
I don't really see the US or France (or many other countries) ever becoming a hereditary monarchy again. Even the communist countries weren't led by dynasties.
In the U.S.A, it seems hereditary monarchies have been replaced with hereditary presidencies(Adams, Harrison, Bush). Probably more loosely related ones to.