The original reCAPTCHA was doing distributed book OCR. It was sold as an altruistic project to help transcribe old books.

And now they're using us to train car driving AI :(

I don't mind car driving AI, why the sad face?

Maybe autonomous train training would be even cooler but it's not like improving tobacco products that only have downsides

I mind working for free.

You'd rather do busywork that you know will definitely not benefit anyone?