Let’s conclude.
I have enabled NSFW content on lemmy.ml and lemmy.world. When I look up specific NSFW content, the results on lemmy.world are way more. Especially for NSFW instances, but also some posts itself. So for some reason, the result on lemmy.ml (and other instance) are censored and filtered. I mean, it’s fine if you don’t look for that content. What makes me wonder is, why there is no information about it when you join an instance.
Ah, thank you for pointing out. Even lemmy.world has some blocked instance. I wonder why, I can’t see nothing wrong with them.
EDIT: ok, some look scamy.