One possible guess would be a random dude having a myriad of accounts,and he sacrifices a few of those by plagiarizing topics,and using his other accounts to spam their way through. All this for bounties maybe. Cases like this have been true before,people managed to get hell a lot of rich.
Instead of totally abandoning Bitcoin Discussion, maybe just keep having discussions with those who want to. Create your own self moderated thread,and discuss stuff. We all came here to discuss about bitcoin and we are doing everything else other than that.
Maybe, I'm not sure. Most of the ones which I've reported have just been newbies posting plagiarized content. Doesn't seem they engage after that. Possibly, someone trying out their bot that they will eventually use for bounties. Some of the sources they are using are actually pretty difficult to find.
If these are individual newbies who don't know whats what yet, I think something like a "search FAQ" bar that opens as you type your topic to recommend threads that ask the same question it might help reduce this. By this I mean something similar to binance when you open a ticket and it recommends similar things in the FAQ as you type your question.
I myself have posted a few bitcoin technical questions which I was sure that someone else has had to ask it in the past, unfortunately finding similar posts is a bit hard in some cases with the massive loads of topics being created, the problem kind of makes itself worse and snowballs on itself. Improving on the search functionality to make it "nicer" would definitely help. I am not sure as to what kind of load this'l add on the servers and how much of a workload it would be on the forums developers though.
On the other note, it is kind of a pity that people are repeat answering a question with the same answer just to get posts for their bounties. (Yes I know I have a sig in my profile, I get it the hypocrisy - I really try add new value to a discussion each time I post). I find that unless it is a very interesting topic and discussion people just read the first post and answers and moves on. I think somehow the idea of adding value to a discussion with a post needs to be reiterated. There is zero value in giving the same answer as everyone else.
This isn't the case. It's not the fact they are asking questions which have been asked before they are literally copy, and pasting questions, discussions and replies from various different sources including the forum. There's been a few Satoshi/Sirius posts that have been copied.