A great quote from the great Moonbus made in the thread below:
Thread 204580
Why does 2+2=4? because we have defined addition that way within a closed, formal system. It tells us nothing at all about reality, much less point to a transcendent mind. Two rain drops falling on the ground next to two more rain drops do not make four rain drops. They make one puddle. Why is that? Because reality, unlike arithmetic, is not a closed, formal system. Pouring two liters of alcohol into two liters of water does not produce four fluid liters. Why is that? Because reality, unlike arithmetic, is not a closed, formal system. It is not possible to deduce anything at all about reality from mathematics alone, much less about any transcendent mind.
Why is it that checkmate is when the king is in check and cannot get out of it? Because we have defined it that way within a closed, formal system. Chess tells you nothing at all about reality. It's just a game we play.
Such is mathematics--it's a game we play with symbols which move according to rigid rules we have defined, albeit a more useful game than chess.
Your interlocutors in the video are making an elementary blunder, confusing the map for the territory, projecting their own (mathematical) models of reality as if they were part of reality itself. They're confusing the ladder, which they use to climb up the tree, for part of the tree itself.