> Very convenient to leave out Amazon in your back of the envelope test, who’s internal metrics were showing a path toward quasi-monopoly profits

Not in the 1990s. The American e-commerce industry was structurally unprofitable prior to the dot-com crash, an event Amazon (and eBay) responded to by fundamentally changing their businesses. Amazon bet on fulfillment. eBay bet on payments. Both represented a vertical integration that illustrates the point–the original model didn't work.

> There’s a difference between being too early vs being nonsense

When answering the question "do the investments make sense," not really. You're losing your money either way.

The American AI industry appears to have "viable economics for profit" without AGI. That doesn't guarantee anyone will earn them. But it's not a meaningless conclusion. (Though I'd personally frame it as a hypothesis I'm leaning towards.)