If they’re not able to cheaply deliver inference (and charge at a premium), how will they be able to sustain their businesses?

I definitely agree that they have a big problem on their hands, and are in deep deep trouble. They are in a position where they must sell a service that is very cheap in order to pay for up front costs that were very expensive.

This is also why the release of Deepseek was such a devastating blow to US AI companies. It proved that:

1. they don't really have a moat that would lock users into their service, or secret special knowledge that prevents other companies from training competitive models. They're in a race to the bottom

2. Deepseek was not only able to train a model of the same caliber, but they were able to do it at a tiny fraction of the cost that US AI companies spent on training US models. Because they spent so much less on training, it means that Deepseek is able to undercut the US companies and offer inference at a much lower price