As someone who follows the startup space (and is thinking of starting their own, non-AI driven startup), the issue is all of the easily solvable problems have already been solved. The only thing that shakes up the tree is when new tech comes along and makes some of the old problems easy to solve.

So take a look at crypto - If you wanted to make a tip bot on Telegram, before crypto that was really hard. You needed to register with something like PayPal, have the recipient register with PayPal, etc etc etc. After crypto it was "Hey this person sent you 5$, use this private key if you want to recover it" (btw I made this service and it was used a lot).

Now look at AI - Imagine making a service that detects CSAM before AI took off. As an aside, I did NOT make this service, but I know a group of people who did. Imagine trying to make this without the AI boom - you'd need millions of images for training data, a PhD in machine learning, and so much more. Now, anyone can make it in their basement.

The point is, investors KNOW the bubble is a bubble and that it will pop. It doesn't matter though. They're looking for people who will solve problems that previously cost 1bln to solve with only 1mln of funding. If even 1% of their companies pay off, they make a profit.