Personally, I do expect a big correction at some point, even if it never reaches the point of bubble bursting. But I have no idea when I expect it to happen, so this isn't, like, an investable thesis.
Technically you are correct. A ponzi is a single entity paying returns from new marks. It is a straight con.
But some systems can be ponzi-like in that they require more and more investment and people get rich by selling into that. Bitcoin is an example.
If this is a bubble and it bursts in a few years, a lot of investors in specific companies, and in the market broadly, will lose a lot of money, but Sam Altman and Jensen Huang will remain very wealthy.
I'm a capitalist and I think there are good reasons for wealth to accrue to those who take risks and drive toward technological progress. But it just also is the case that they are incentivized to hype their companies, even if it risks getting out over their skis and leads to a bubble which eventually bursts. There are just have lots of ways to extract wealth prior to a bubble bursting, so the downsides of unwarranted hype are not as acute as they might otherwise be.