"API requests will only get cheaper"
You've somehow missed all the "enshitification" processes Cory Doctorow and others have been documenting?
"Here is how platforms die: first, they are good to their users; then they abuse their users to make things better for their business customers; finally, they abuse those business customers to claw back all the value for themselves. Then, they die. I call this enshittification."
OpenAI (et al.) are all deeply in the "First, they are good to their users" stage of their business plan, but they WILL. NOT. STAY. THERE. Whatever product relying on OpenAI you can offer/build/grow into a business, sooner or later you're going to be squeezed for every cent in profit, in the same way as companies who were convinced Facebook was a great alternative to running their own web presence are these days - having to pay to ensure content that people who've like and subscribed to their pages end up seeing anything they post.
Your $20 subscription is not even close to covering electricity costs - never mind covering capitalisation costs for $1.6 billion data centres with another $1.6 billion dollars worth of GPUs to put in them. (Think about it. Even if that 3.2 billion dollar datacenter was funded borrowing at only 1% - you'd need over 130,000 paying subscribers at $20/month just to cover the interest on the loans.)