I'll say one thing about the possibility of Bigfoot existing.
If you're sitting in a house somewhere in the suburbs or any kind of populated area the notion of a creature like that seems pretty distant.
But, if you are deep in a wilderness, somewhere where the cell signals don't reach, the trees and mountains stretch on for many miles and help is a long way away then you might suddenly start to believe that maybe modern man doesn't really rule his environment quite as much as you thought before you left home.
Primitive cultures all over the world have for ages passed on stories about a huge, hairy ape man that lives where men seldom go. Russia, Australia, Indochina, All over North America and many other places. Stories that originated when these cultures could not communicate.
Maybe there is something in the human brain that deceives, that wants to believe that such, fairly specific creatures are real. That makes us see things that aren't there. Something in our DNA. Could be some protective instincts left over from primitive man-- who had to survive real monsters -- that evolution has left intact.
I find that notion damned interesting, but not as interesting as if there is actually an incredibly cunning, unknown species that desperately wants to steer clear of us and possesses extraordinary sensory capabilities that allow it to, just barely, accomplish that by living in places that makes contact very rare and all on their terms. Typically, the middle of the night in the middle of nowhere.
Either possibility is on the table to me. Science finds previously unknown species fairly regularly these days and this one could be a great deal smarter than any of those because they are part human.
I just like a good story. Either way.