I often encounter an off-topic or otherwise unsuitable post, and comment so on the post. The OP might immediately reply asking for the best course of action.
Should I tell the OP to delete the question? Should I leave it to those who have moderation powers?
If I were to leave the question, they might receive an answer and my judgement may be proven incorrect.
If I were to tell them to delete immediately, their post would not be seen by most of the community.