Newbies in the examples you have described definitely deserves to be guided. But I was talking about deliberate plagiarism or using AI to "write" posts. When someone does this, it means that he is aware of what he is doing. Does he need any guidance or advice? Will it be a discovery for him if other forum members warn him that this is unacceptable? I doubt all of that. That is why I see more use in just reporting such users to moderator. But of course I am not talking here about some users making mistakes, but who are ready to learn and are thankful to the guides which over users provide to them.
In that case, we also report their posts. But, you still didn't get the other fact I have mentioned which is the unwritten rules of the forum. Take merit abuse for example. The forum allows multiple accounts. What if you see someone created a topic and replied with another account and sent some merits from one account to another? Isn't it unethical?
Sometimes we know this is abuse. But, do you think we could report it without any evidence? We can only report once it gets bigger and obvious to everyone that the account is someone managed by the same person. Talking yourself, sending merits, trust inclusions and many other unethical things that are not listed on the forum rules still frowned upon.