You can also think of it in terms of 1 Corinthians 13:11. Maturity, and the turning of generations, does something to an organization. Christianity began as an apocalypse cult, after all, promising hope of the afterlife for the downtrodden; it wasn't until Constantine was converted that it started to learn how to be a state religion; and not until Martin Luther and Henry VII did it learn to be just a religion. (The exile into Babylon and the dissolution of the Caliphate had similar effects on Judaism and Islam.)
In other words, they were forced to let go of their control simply because of historical circumstance. Straight through World War 2, the Vatican continued to exert a very strong influence on European nations... because the Pope was everyone's ambassador, even if he could no longer threaten excommunication with meaningful clout.
Scientology has not had these experiences. It is young and not officially descended from any known religion, so "sect" would be an incorrect term except in cases where you consider the entire whole of Judaism or Christianity a sect. It is dominated by personality cults, from the original of L. Ron Hubbard to its scheme of hooking celebrities to be spokespersons.