Your solutions become more and more unfeasable. People would report less or anything at all if it costs money to do so, defeating the whole purpose of a report function.

And if you think you're being smart by gifting them money or (more likely) your "in-game" currency for "good" reports, it's even worse! They will game the system when there's money to be made, who stops a bad actor from reporting their own poison? Also who's going to review the reports and even if they finance people or AI systems to do that, isn't that bottlenecking new models if they don't want the poison training data to grow faster than it can be fixed? Let me make a claim here: nothing beats fact checking humans to this day or probably ever.

You got to understand that there comes a point when you can't beat entropy! Unless of course you live on someone else's money. ;)