“Bigfoot” does not exist as a separate species. If there were more than one they would be much easier to find than just one. If there is only one it would have to be practically immortal given the amount of time that it has been around. Therefore it would have to be supernatural. That puts it in the realm of ghosts and vampires. I don’t think MIT will find them either.
If there were more than one Bigfoot they would have to reproduce. There would be mama Bigfoots and daddy Bigfoots and baby Bigfoots. Whole Bigfoot families. Teenage Bigfoot gangs. It wouldn’t be difficult at all to find them. All it would take would be a mama Bigfoot dying in an accident to strand a young Bigfoot which would then be found by people.
The other arguments are that the area is so vast that they elude detection and that they are so smart that they avoid humans. Those are speculative at best and are not proof any more than trying to prove God exists by saying everything is too complex to be accidental.
That may have happened at a Canadian lumber camp back in the 1800's. A young creature fitting the description of bigfoot was found by lumbermen and taken to their camp. They named it Jacko. The story can be found in Ivan T. Sanderson's book, Abominable Snowmen, Legend Come To Life. It was written back in the sixties, I think.
I don't recall what happened to Jacko, though, and my library can't find the book.