I think there's an assumption that current costs, which are high, will remain high.
Most of that seems to be going to model development, rather than model operation, which is the product we all use.
To me the most likely option will be, that development slows and prices rise somewhat, as they can't keep burning cash forever. But I'm willing to pay a little bit more, considering how powerful the tool is.
I'm guessing that might be so in certain professions, but I would expect the employer to pay for that. For the rest of us, it seems unlikely. At least for me, I don't have a need of a device to generate text for me. And I bet most people are are in the same boat as me.
I think that AI is going to become just another utility people pay to stay relevant. Same as their internet, electricity or gas.