Who actually plagiarised? Those are very lazy and don't want to take time to research and just copy and paste from other sources without giving credit. Even if you use AI and copy-paste data here, that will be considered plagiarism as well. In some cases you can use AI to know the exact data that won't be considered plagiarism. For example, you asked AI what the price of Bitcoin was one year ago exactly. So AI will collect data and show you the price. Only that kind of data won't consider plagiarism. Otherwise, if you ask AI to make a post and you reverse some words, it will consider it plagiarism.
If anyone doesn't understand a particular topic of discussion in a thread, they could easily google it or ask AI, use 15 to 20 mins to read about the topic and return to the forum to make organic contribution.
I thought that the reason why people were plagiarizing in the past was because of the lack of research tools and platform. Now that even google has integrated AI, research shouldn't be difficult and the rate of plagiarism is supposed to reduce drastically.
Why is there still plagiarism?
What you suggested will still be considered plagiarism. You make a post through AI and reverse it yourself or through some other tool, which will be considered plagiarism. Because this isn't your content actually, and you aren't giving the credit to the AI.