The LLM bubble is the Weekend at Bernies version of the dotcom boom, which happened on DIALUP internet. The first linksys router came out the year of the crash (before which wifi and always-on broadband connections weren't readily available). The first modern smartphones came out 6 years later. The dotcom crash happened with a decade of technological growth left.
But there's no exponential LLM growth, only linear returns for linear cost increases. Silicon Valley beating a dead business model.