After sharing and enjoying people share their prompts in various communities for 2-3 months, I hate this business model.

Why? You can still do what you want to do - this sort of thing just helps people who perhaps don't have the ability or inclination to capably form their own concepts.

It's much like hiring a painter, a writer or a web designer... .

At least, it's interesting for me to see what may be the beginnings of a new job class. I've been wondering where all this ML/AI business might take us.

Because it provides an incentive to not share knowledge, but instead hide it behind micro transactions.

For some, sure - but I've derived far more for free on the internet over my 25 years on it than I have ever paid for, and I don't imagine that'd change here.