The wealth the Dotcom boom left behind wasn't in dial up modems or internet over the telephone, it was in the huge amounts of high speed fiber optic networks that were laid down. I think a lot of that infrastructure is still in use today, fiber optic cables can last 30 years or more.
In the late 90s to 2001? Many people were still using modems at that time. Cable or DSL wasn't even an option for a considerable percentage of the population.
Low Global Penetration: Only 361 million people had internet access worldwide in 2000, a small fraction of the global population.
Specific Country Examples
United States: The US had a significant portion of the world's internet users, making up 31.1% of all global users in 2000. Its penetration rate was 43.1%.
Not still using, flat out modemless. Lots of guys got their hand on a mouse for the first time only after Windows XP launched. Which was after the collapse.
The current AI bubble is leading to trained models that won't be feasible to retrain for a decade or longer after the bubble bursts.