I don't know how to make sense of this level of investment. I feel that I lack the proper conceptual framework to make sense of the purchasing power of half a trillion USD in this context.
Maybe your calibration isn't poor. Maybe they really are all wrong but there's a tendency here to these these people behind the scenes are all charlatans, fueling hype without equal substance hoping to make a quick buck before it all comes crashing down, but i don't think that's true at all. I think these people really genuinely believe they're going to get there. And if you genuinely think that, them this kind of investment isn't so crazy.
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.