In addition to all that, other investments would be made in other sectors. I'm sure a huge bulk of investment into NVDA in particular is strictly because of the five figure percentage growth it has enjoyed over the last 6 years after all, with the whole chip argument being the fig leaf over the rampant greedy pumping. It has exploded like some lucky shitcoin and that's enough to drive investor action on massive scale after all. We are in the world where shitcoins are listed along with the blue chip tickers on bloomberg news. Everyone is greedy right now. Gambling on every scale from every direction. Most corrupt president in history to boot openly insider trading; water is full of chum and blood right now.
More people, more awareness about how money works, and more dependence on global investors.
Everyone invests so they can have more in the future, so yes, it's not crazy to imagine people will invest in a company that's growing without knowing any other details.
Why did it grow so large is the question. Why do some of these companies attract all the talent and grow so large and dominate the future is the question.
It's because we're all limited on time and greedy.