Not everyone in the world has $20/month of disposable income, nor does everyone have the disposable time to learn how to make it hugely useful to them.
Also, these are just the numbers for OpenAI. A lot of others are ok with e.g. "paying" for it by going to Google's AI Mode, and getting some ads.
So ChatGPT cannot deliver you $20/month worth of productivity to offset the cost? That's at least my point, for developers, businesses and a ton of use cases, access to a good AI is worth every penny, because it easily pays for itself. For the average consumer, that's just not true, apparently.
Also, these are just the numbers for OpenAI. A lot of others are ok with e.g. "paying" for it by going to Google's AI Mode, and getting some ads.