I think it’s a fine layman comparison to Nazi Germany because it gets the message across that they’re doing bad things based on religion, and for most people the only evil regime they know much about is Nazi Germany.

The more nuanced take though is that Nazi Germany was extremely unique in that they industrialized killing. They had a supply chain for genocide, a state-run business of exterminating Jewish people (and some others) for the sole purpose of killing them. The Chinese camps are an evil more like Soviet or other re-education camps that have existed in history, more evil in some ways in that they involve considerably more torture but less cosmically evil in that they are oriented around brainwashing, not necessarily industrialized killing for killing’s sake. So far as we know right now.