OpenAI has ~4B of revenue already, and they aren't even monetizing aggressively. Facebook has an infinite money glitch, and can afford to put billions in the ground in pursuit of moonshots and Zuck's own vanity projects. Google is Google, and xAI is Elon Musk. The most vulnerable frontier lab is probably Anthropic, and Anthropic is still backed by Amazon and, counterintuitively, also Google.
At the same time: there is a glut of questionable AI startups, extreme failure rate is likely - but they aren't the bulk of the market, not by a long shot. The bulk of the "AI money" is concentrated at either the frontier labs themselves, or companies providing equipment and services to them.
The only way I see for the "bubble to pop" is for multiple frontier labs to get fucked at the same time, and I just don't see that happening as it is.