Just as interesting are all the instances where stories gained dozens of upvotes but very few comments, because they disappeared from the front page within a few hours after rising to the first spot. It's very easy to see even from the outside, if you simply filter for stories that are ranked lower than other stories that have a lower score, are older, and have more comments. Try this on for size:
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
That even gets a few results of you increase the score to 100, e.g.
https://news.ycombinator.com/item?id=20304526
I remember seeing that just go poof back then. One moment it's at the top, then it quickly sinks, then it's on page 7824.
Just about any subject is discussed a great deal here, because "a great deal" is no hard qualifier at all. But I know few subjects so consistently suppressed and messed with here as Chinese totalitarianism. You could convince me otherwise with a database dump, by making votes and flags public, but not just with mere claims and saying you didn't notice anything. Maybe you didn't, but that really just proves you didn't notice it.