I suspect a lot of this is due to large amounts of liquidity sloshing around looking for returns. We are still dealing with the consequences of the ZIRP (Zero Interest Rate Policy) and QE (Quantitative Easing) where money to support the economy through the Great Financial Crisis and Covid was largely funneled in to the top, causing the 'everything bubble'. The rich got (a lot) richer, and now have to find something to do with that wealth. The immeasurable returns promised by LLMs (in return for biblical amounts of investment) fits that bill very well.