The last scientific developments that anyone cared about were nuclear weapons and ballistic missiles to deliver nuclear weapons. The Cold War kept the economy puffed up for a few decades on the back of that. The next economic bubble will depend upon the next plausible promise to transform the nature of war and with it, the nature of geopolitics. Insofar as anyone is interested in AI, this is why; but it is very thin. Its promise is very indirect, conditional, and hypothetical. Those who want to believe will believe, but the big, agonizingly simplistic civilizational story is hard to find and tell.
What about lithium ion batteries? Both a scientific development that people care about, and also currently transforming the nature of war (via drones). Is it a bubble?