Things are moving too fast to meaningfully talk about unit economics here.

My consumer-level MacBook Pro can run inference locally on models that would have been state-of-the-art anywhere just a little over a year ago.

Yet, hosted inference is definitely useful and also can benefit from economies of scale.

Also: model training is expensive and the economic reasons for doing so are complex (otherwise why release open weights?)

This is an high dimensional space, and unit economics are predicated on reducing to a few meaningful dimensions.