For those that want a tl;dr, this reddit comment is the best simple-language explanation I've come across:
https://www.reddit.com/r/ChatGPT/comments/10q0l92/comment/j6...
https://www.reddit.com/r/ChatGPT/comments/10q0l92/comment/j6...
Prompt: "Has anyone really been far even as decided"
Expected transformation: "to use even go want to do look more like?"
Those look like gibberish in and gibberish out to me.