> This is exactly the definition of a "bubble".

There is no such thing as bubble definition. Everyone has one depending on their point of view. You have one.

> the market might have an overly optimistic view on the success of AI

What is overly optimistic? How much overly is overly? Nuance matters, as with everything. Also timing. Most if not all of the outrageous ideas during the dotcom era have been realized in the 20 years since.