system
A chat on 4chan
human
My favorite bit of loopy time travel thinking goes like this:
Time travel will never be invented, because EITHER:

TIME TRAVEL IS NOT POSSIBLE, in which case of course it is not going to be invented, or
TIME TRAVEL IS POSSIBLE, in which case every time somebody goes back in time to before time travel was invented they reset the timeline, which is now constantly in flux and cannot settle down into one state, until by chance it comes across a timeline in which time travel, though possible, is never invented -- and then it is locked into that one forever.
gpt
You're almost right, but the most important thing that governs the existence of time travel in the present comes down to a specific choice.

It's never impossible, it just carries a very important toll. One that can not be paid lightly.