Because the check helps train their robots.

There is a captcha that doesn't ask, because, y'know...it knows.

You probably don't notice it, because it just chills quietly in the corner.

That makes me think, if they can't tell we're humans or bots while they're harvesting our data, how easily could we poison their data with fake people generating false data?

Gotta delete the Google account!

And it can't trascribe my name which it knows when converting my voice mails to text >_>