IMO — There is no such thing as "independent" churches. It's a very big ecosystem, an ecosystem that has forced us to invent the word "Secularism". Not sure if you have forgotten...
Is your claim that "secularism" means that it's okay for China to have state-approved Christian churches?
If not, can you state exactly what you mean, and whether you believe it's good for China to crack down on non-state-approved churches while also having state-approved churches?
