It's more they had to wait for processing power to catch up.

One of my bit older friends got an AI doctorate in the 00s, and would always lament a business would never bother reading his thesis, they'd just end up recreating what he did in a few weeks themselves.

It's easy to forget now that in the 90s//00s/10s AI research was mainly viewed as a waste of time. The recurring joke was that general AI was just 20 years away, and had been for the last few decades.