The flip side of that is that at least half of all white-collar work was already useless before AI. If it hasn't already been eliminated, there's no reason to assume a-priori that AI can eliminate it.
If half of all white-collar work was useless before AI, and AI can replace those workers, then one can logically conclude that AI is useless.
If half of all white-collar work was useless before AI, and AI can replace those workers, then one can logically conclude that AI is useless.