I don’t believe this will become the next big thing for CAPTCHAs anytime soon, primarily due to security flaws, privacy concerns, and accessibility barriers.
The article mentions: “Attention: This MediaPipe Solutions Preview is an early release.”
If you don’t trust Google, simply using a fake hand that looks real might be enough to fool the system. Also, set up the camera before recording so it doesn’t capture audio.
That way, you protect yourself and the people around you (if applicable).
The other way—just don’t give it access and that’s that.