This deals with half of one of the three scaling factors only. Presumably data production (choosing your training data, etc), model size, and training time/power still contribute huge costs. Who's investing that cash if open-source models will distill out enough to compete without the investment costs?

There is a community of people who compile LoRAs of their favorite subjects/styles in order to fine tune models. There is currently a bit of a gap between LOrA creation an integration of that data into larger models but I can see serious hobbyists stepping up to that plate soon.