You do realize there are a good number of crypto billionaires right?
I mean I get your point and it kinda stands, but the latest batch of crypo fueled wealthy people are less the pioneer/early movers and more the "I'll create a crypto product nobody understands and, boom it has a market cap of a couple hundred billion!". And since you can trade whatever crypto you want for eth, all you have to do is convince people your coin is worth something and you can do exactly the above thing.
There are a good number of startup billionaires too, so why not just make a Google?
I think you are falling prey to selection bias. Yes there are many scammy projects that made a few people rich, and a handful of non scammy projects, but the vast majority do not work.
Start a new stablecoin (or have connections with one of the existing ones) and promise everyone that you have dollars backing it, then mint $320 million of that coin even though you don't actually have dollars backing it.
The recipe for creating fake dollars in crypto is pretty well established at this point