Neither is very likely in my opinion.

I think the tech will work well for some tasks where a formal feedback loop exists (such as coding). In other areas it will take many years to adapt business processes and roles to make the best use of this technology. The total productivity boost could be around 1% p.a similar to the industrial revolution of the 19th century.

Stock prices could be at risk not from lack of demand but because the data center buildout is bound to slow dramatically as we come up against some serious bottlenecks like energy, grid, fab capacity, permissions, etc. Not much will have to be written off, but the delays could cause big problems for debt funded projects and companies.

This slowdown will allow the economy and the workforce to evolve away from execution and towards planning, strategy, research and development, idea generation, experimentation, oversight as well as manually handling a million exceptions and gaps left by current AI models.

I don't think there has ever been a tech boom without a tech bust. But that's not the same thing as the tech not working or causing economic collapse. Maybe this time is different. Who knows.