The point is that while both ChatGPT and Copilot are powered by the same model, they are different products, and one can be useful for one task where the other isn't. Just because someone doesn't find ChatGPT useful doesn't mean they can't find Copilot useful, since there are differences between the two products even if they are powered by the same model.
You should never conflate products with models, it leads to invalid comparisons between models and products. Which for some reason has been the norm. How many times have you heard someone ask "How much worse is Llama than ChatGPT?"?