> Why do you think these private entities are willing to invest the massive capital it takes to keep the frontier advancing at that rate?

Because whether they make 100x or 200x they make a shitload of money.

> Why wouldn't NVIDIA be a solid steward of that capital given their track record?

The problem isn't who is the steward of the capital. The problem is that economically efficient thing to do for a single company is (given sufficient fab capacity, and a monopoly) to raise prices to extract a greater share of the pie at the expense of shrinking the size of the pie. I'm not worried about who takes the profit, I'm worried about the size of the pie.

>Why wouldn't NVIDIA be a solid steward of that capital given their track record?

Past performance is not indicative of future results.