If AI companies go bust so will those retirements accounts (and the economy) So I think it is likely that AI companies will be bailed out when the bubble bursts.
I guess the lesson multinationals learned from the 2008 financial crisis is that if you fail is better to fail really really really big.
Tech stocks, and stocks in general, are overwhelmingly held by wealthy people who are way more exposed to crash than working class folks. The median retiree is much more reliant on social security and safe investments than they are on NASDAQ. Even if a few big tech companies go to zero it will only have a modest impact on their finances.
Obviously there would be knock on effects of a major crash that are hard to predict, but people inside the AI bubble wildly overrate how invested most Americans are in their success.