Of course the steam engine was revolutionary. That doesn’t excuse or legitimize the nonsense.
Dropbox or SpaceX wasn't valued at many trillions of dollars though. Just because its very useful doesn't mean it lives up to the biggest hype ever in human history in terms of monetary investment.
AI is here to stay, and long term, it's likely going to revolutionize almost all parts of the job market. But to get there... I'm really not sure what a reasonable time estimate would be. I can see it take something like 3 years, which would make current evaluation plausible, but I wouldn't bet on it.
It'd bet on it taking a tad longer, but I strongly suspect by 10-20 yrs, we'll get there.
Under that time horizon, it feels overvalued and hyped, because the winner's of this revolution might not even have been founded yet.