Unlike Google, hCaptcha isn't running an ad network "on the side" of their bot management business :) joking aside, hCaptcha is an extremely privacy-conscious operation, Google is not.
We are working through the IETF and directly with browser makers to support provably private options like Privacy Pass, and are currently the only CAPTCHA service to support this.
Similarly, on the enterprise side we offer various technical options to let our enterprise customers guarantee exactly what data we can and cannot see.
(disclaimer: work there, comments not official, etc.)