It absolutely diminishes the AI Doom story, but it also diminishes the AI Will Be The Golden Goose story, they are two sides of the same coin. The AI companies can only capture that surplus if there are not competitive substitutes available.
In the same way that Amazon gets rich taking ElasticSearch for free and charging for hosting, Amazon will take free models and charge to host them. The companies building frontier models have massive R&D costs and no moat.