"Google had the best search engine, it became a centre of gravity..."

Almost no one made serious attempts at competing with Google. And not because of network effects or any other hard blocker. In the early 2000s, the industry just wasn't mature enough to heavily fund serious competition.

By the 2020s the industry has funding and founders ready to jump on any huge opportunity that presents itself.

There are of course downsides, but this competitive landscape in AI seems like a huge net win for users in terms of lower costs and faster progress.