Blocking users hiding their activity in all areas.

YES!

 ASTER:

https://mydramalist.com/discussions/suggestions/109381-delete-block already suggested

kind of, but not fully. Since your suggestion is not just hiding activity. I agree with some, not all. That's why making a suggestion post with more than one suggestion is a tricky thing 😅

"In that case, implement a system where, as soon as a user blocks you, all your comments become invisible not only to the blocker but also to everyone else." < strongly against this one, because then the block option can be used to simply silence other people and the whole conversations. I am also not sure how could this possibly be implemented. The whole comment thread would still be visible, just the blocked person comments would not? That would lead to more confusion and issues. It would mean the person that blocked the user can in that comment thread create their own narration of what happened, and no one can verify if it's correct, since the comments of person who was blocked are not visible.