How about we start thinking from newbies perspectives. The forum is so big. You say search the forum. If it's first time or new to bitcoin/cryptocurrency and somehow found the forum, how do they know to navigate through all the sub-sections and jargons?
When people are first learning about crypto, they are excited, nervous, they want information, they have questions. Most are not expert information diggers. It's difficult to understand the forum layout, relevant sub forums. You can't just google anything and everything and read some websites. I would rather post on some forum, get more replies and explanation from members there.
So, if you think a newbie is asking a question which has already been asked a hundreds of times, then as an experienced member you could point to that thread, ask the mod to lock the thread. Most of were newbies and most of us posted and asked seeming stupid things, asked some common sense questions. So, we should understand that most are genuine newbies posting questions that they genuinely want answers for.
Even to me many sections seems like alien places to me, I still only go to sections relevant to me. Most of the sections I have no interest whatsoever. Therefore, I think newbies are confused when trying to navigate through the forum. So, we should be understanding of their viewpoint.
Yes, there are also some newbie accounts with shit posts. Because of the posts and merit requirements for member ranking upgrades, there's no way to avoid some new members trying to increase their activity level with low quality post. Unfortunately, this is just a side effect we have to live with.