I think he's implying the money in AI is all spending from OpenAI+Anthropic who get it from investors. But those two have annualized revenue of about $26bn and $74bn or about $100bn total which presumably represents actual customer demand for the product.
That's $100bn revenue on about $1tn capex so far which isn't enough to make it profitable in itself but the things growing like crazy so you'd expect that. $100bn is about 0.08% of world GDP so if AI customer demand grows to 1% of GDP that's up 12x from here.