It was my impression that OpenAI was struggling to make money on their $200 pro subscription, because they've underestimate how much people would use it (https://www.theregister.com/2025/01/06/altman_gpt_profits/).

So I do question if OpenAI is able to make a profit, even if you remove training and R&D. The $20 plan may be more profitable, but now it will need to cover the R&D and training, plus whatever they lose on Pro.