Demand increased, everyone built new fabs, then prices dropped and they couldn't pay off their investments. Many went out of business. It happened in the 80s, it happened in the 90s, it happened in the 2000s.
Now there's only three manufacturers left, and they know very well that demand for their product tends to be cyclical.
I've been in the industry for 30 years and I've worked at companies with fabs were demand was high and customers would only get 30% of what they ordered. Then just 2 years later our fab was only running at 50% capacity and losing money. It takes about $20 billion and 3-4 years to make a modern new fab. If you think that AI is a bubble then do you want to be left with a shiny new factory and no products to sell because demand has collapsed?
The lawsuits in the past prove that statement to not be basically but actually.