The nice thing would be having a basic level of trust that the person you're interviewing is an actual person. If all job interviews need to start off with a CAPTCHA we'll be in a bad place.
I imagine these shell-game interview tricks work really well at large companies where the HR screen is considered to be perfect and thus managers rejecting numerous candidates at the interview layer will be penalized in some manner. "Look, Polly on the Cloud-X-AI team accepted 80% of applicants that reached the interview phase - why is your team accepting just 20%? Is this a culture fit issue that we'll need to intervene on?"
I imagine these shell-game interview tricks work really well at large companies where the HR screen is considered to be perfect and thus managers rejecting numerous candidates at the interview layer will be penalized in some manner. "Look, Polly on the Cloud-X-AI team accepted 80% of applicants that reached the interview phase - why is your team accepting just 20%? Is this a culture fit issue that we'll need to intervene on?"