This seems generic enough that it could almost be applied to any use case. Have you considered catpcha as a use case?

If you're talking about CAPTCHA solving as a service, that already exists, and the cost is measured in mere dollars per thousand CAPTCHAs solved.

that's a great idea - I put together one example for getting an MFA code for a website, but the captcha thing "pull a human into a web session" is something I've wanted to play with for a while