Yeah but the videos are more than just "air" - they don't move until applied moisture/heat then they move on their own without more. Kind of like those Japanese dishes with little flakes on them?
Some things move because they're alive. Some living things don't move. Some non-living things move, too.
Movement is not conclusive evidence of life. These videos - setting aside the legitimacy of 4chan for a moment - demonstrate "if you put the fiber in water, it moves", not "these fibers are alive".