I have heard that most of the "solving" you are doing is mostly to generate mouse movements and click timing that can be tracked and analysed to determine uniqueness that implies non-automation. That's probably the reason keyboard shortcuts aren't the default on 3x3 captchas. (There's a userscript I used previously that would let me hit a numpad button to click on corresponding images. It was great) Data google knows about you from elsewhere on the web is also used to determine humanity.

Even if AI blows past the percentage of the time recaptcha considers a failure (IIRC, 0.1%) it's not going away, since it cuts down on so much low-effort spam. See also: forums that use "What is 2+3?" as a captcha on registration forms.