The people who fell for this absurdity are uneducated, exceedingly gullible, and in need of mental health help.
Time travel has been a SF trope since H G Wells wrote The Time Machine in 1895.
There have been all kinds of claims of secret government and private research on this topic since then.
That includes a wide variety of folks with entertaining stories about how they are time travelers.
One of the latest variants are the claims of “twenty and back” technology which....
If you are interested you can check on that for yourself.
While I do not necessarily believe any of the stories I am in no rush to dismiss them as crazy either.
If the tech was invented in the future and time travel brought it back—who knows?
Physics professionals have wild debates on the nature of time—there are several different theories on how it works and they are truly “crazy” to folks who have not heard them before....
https://www.quantamagazine.org/a-debate-over-the-physics-of-time-20160719/