Except for the invasion of my time and attention, used to train Google's AI to get better at recognizing traffic signals. I took that as the main point of the article.
v3 is "invisible" and is supposed to be deployed to every page on the site, and the site is the one who decides how to punish you for not matching their normal audience.
Not just invisible but unlike "invisible recaptcha" which was kinda between v2 and v3 which does spawn a challenge on its own, but v3 is entirely non interactive and as you said the site/admin decides the punishment.
v3 is "invisible" and is supposed to be deployed to every page on the site, and the site is the one who decides how to punish you for not matching their normal audience.