And he's right (and the sources he points out), that some bubbles are good. They end up being a way to pull in a large amount of capital to build out something completely new, but still unsure where the future will lead.
A speculative example could be AI ends up failing and crashing out, but not until we build out huge DCs and power generation that is used on the next valuable idea that wouldn't be possible w/o the DCs and power generation already existing.
In the event of a crash, the current generation of cards will still be just fine for a wide variety of ai/ml tasks. The main problem is that we'll have more than we know what to do with if someone has to sell of their million card mega cluster...
The usual argument is the investment creates value beyond that captured by the investors so society is better off. Like investors spend $10 bn building the internet and only get $9 bn back but things like Wikipedia have a value to society >$1 bn.
A speculative example could be AI ends up failing and crashing out, but not until we build out huge DCs and power generation that is used on the next valuable idea that wouldn't be possible w/o the DCs and power generation already existing.