"Interchangeable", or, at greater length:
Equivalent \E*quiv"a*lent\ ([-e]*kw[i^]v"[.a]*lent), a. [L.
aequivalens, -entis, p. pr. of aequivalere to have equal
power; aequus equal + valere to be strong, be worth: cf. F.
['e]quivalent. See {Equal}, and {Valiant}.]
1. Equal in worth or value, force, power, effect, import, and
the like; alike in significance and value; of the same
import or meaning.
[1913 Webster]
For now to serve and to minister, servile and
ministerial, are terms equivalent. --South.
[1913 Webster]
The Cultural Revolution did not upend and destroy an existing culture and whole civilizations, but neither did the other events you're describing.
A big difference between the Cultural Revolution and things like the French Revolution and the Russian Revolution is that the Cultural Revolution entrenched the existing leader of PRC, while the French and Russian Revolutions overthrew the existing leaders, which is generally considered to be one of the most important things about them. The Cultural Revolution was more akin to Stalin's purges of his opposition within the Party, the Night of the Long Knives, the Salem witch trials, the Cambodian Killing Fields (as CamperBob2 pointed out), the Terror, or the Roman Dominate, but it has important differences from each of them. For example, the Night of the Long Knives lasted three days, the Cultural Revolution lasted 10 years, and the Dominate lasted about 300 years.