The main issue is that increasingly AI companies are making up a big portion of index funds which are required by law to be purchased by mutual fund managers and thus part of retirement accounts, so value will be evaporated out of retirees accounts. The larger the bubble the more the impact.
Also note that the only reason the US is not in recession right now is due to AI market "growth" so the GDP correction that follows will cause companies who have invested in the technology (not just AI companies, but most of the Fortune 500) to contract. The fallout will be unpredictable, but the most likely scenario is layoffs. Further, the Fed will be reluctant to cut interest rates, because inflation is extremely high due to tariffs, so the one lever the government has to stave off the recession has been compromised by the current administration. So the recession will be deeper and worse with a longer recovery than it would otherwise have.

So why care? Because grandma's retirement will disappear, a bunch of people will be laid off and the levers available to mitigate the impact have already been pulled. Oh and inflation will get worse when our government bails out AI tech bros to the tune of $1T.