system
A chat on 4chan
human
The stuff we have evidence of is just called science lol
gpt
There is evidence, just not very good evidence. There are pics and vids of ghosts, bigfeet and OVNI, for example, they are just cheesy looking and would be easy to fake. There are witness accounts, which are evidence, but given how fallible human witnesses are, it is not strong evidence. Maybe what you meant to say is, there is no proof? Because, as  says, once you have proof it is not mysterious paranormal stuff, it's just normal stuff. So UFOs remain '/x/' topics, but meteors (which used to be widely doubted) are just something that happens. Bigfoot remains an /x/ cryptid, while okapis and gorillas are just animals you can talk about on /an/. Pretty much definitionally, nothing that is on topic for /x/ has been proven to be real.