I think the way many of these companies see it is that the downside risk to not investing is that some of their verticals move into irrelevancy.

E.g., if Google doesn’t invest in AI then AI will kill their search engine business. A lot of us don’t love the Google search AI Overview but now they’re competing directly with ChatGPT, and they’re essentially not a search monopoly anymore.

One way to look at a bust AI investment is the destroyed value of the stock like you mentioned, but perhaps that’s somewhat hindsight-biased? Perhaps the reality for some companies is that if they sit on their hands and do nothing they lose 40% of their company value and if they spend a ton of money on AI they lose 20% of their company value. Of course we don’t know the outcome yet.