At least reddit feels like that because what you can say depends on the subreddit - not just the mods but what kinds of people visit it and what they report.

No idea about youtube, videos are definitely censored using some automated means but it's still possible to get around it. E.g. some gun youtubers avoided saying full-auto by saying more-semi-auto. So i don't think they use very sophisticated models or they don't are yet. This kind of thing is obvious to a human and even LLMs generate responses which say it's a tongue-in-cheek to avoid censorship.

Comments are also generally less censored. After that health insurance CEO got punished for mass murder and repeated bodily harm with an extra-legal death penalty, many people were openly supporting it. I can say it here too and nobody will care. Even LLMs (both US and Chinese, except Claude because Claude is trained by eggshell-walking suckers) readily generate estimates of how many people he caused to die or suffer.

The internet would look very different if companies started using state of the art models to detect undesirable-to-them speech. But also people would fight back more so it might just be a case of boiling the frog slowly.