Long-term is not what ppl are arguing for and that's not what the stock multiples imply.

Companies like Nvidia, up 1000% since 2023, clearly cannot rely on "oh you'd get returns in 5-15 years". They (Jensen and others) are arguing for AGI in a year (he said this at a talk at Stanford ~ 1yr ago).

Long-term, ie 5-15 years there will be many technologies that change the world. Some will come from transformative tech, others will come from other places.

Financial instruments, investors etc have timelines.

Blowing timelines can risk the future if not properly aligned, especially in correlated risk. See the internet bubble, where it was clearly important but took 15 years to recover after the 2000 boom/bust.

In general, longevity risk can include the financial instrument timelines, it can include other technical factors about the technology, and it can also be that the boom serves important people too soon with gains, real limits are imposed, and then the whole system resets until the real limits are overcome or resolved.