In Firefox, log out of your google account, block cookies and enable the anti-fingerprinting features. Or just browse with Tor Browser.
You will start getting challenged more often, you'll find you're asked to solve several multi-select challenges in a row even if you get them right, the multi-select challenges will replace tiles after you select them, and the tiles will start fading in and out very slowly.
I have noticed recently that when using Firefox the need to repeatedly spot traffic lights or fire hydrants 5 or 6 times in a row seems to have gone away. It now seems that I only need to do it once now so perhaps someone at Google fixed the glitch?
The most insidious thing about this two-tiered surveillance society is that its effects are invisible to people in the "good" class, and they insist on remaining ignorant of what happens if you're not in that class.
Google still has plenty of other tracking points on you. And of course reCAPTCHA looks reasonable to a prospective developer - it wouldn't be adopted otherwise!
If someone tells you it routinely takes 30 seconds to solve, you should really just accept their experience rather than discarding it with "works fine for me!". If you still need to see it with your own eyes, go setup a TOR browser and become one of the undesirables, rather than just imagining. You just might end up adopting the marginalized view.
Try using Tor and a real website that is using reCAPTCHA (I don't think they have their actual scoring system enabled on the demo). GP posted a link to a video of someone solving a single reCAPTCHA prompt for 2.5 minutes. I also regularly have to solve several CAPTCHAs in a row, often with increasing levels of image distortion.
Before being so brazenly dismissive of other people's experiences, take the few measly minutes it would take to actually try it out. Even doing a simple Google search with Tor Browser usually gives you a reCAPTCHA to solve.
I've experienced that in the past, without using tor, but using Firefox. I go to great lengths to block anything Google. Google Fonts, Google CDNs (and I now use Decentraleyes so CDNs are mostly not even reached). I have to explicitly unblock reCAPTCHA scripts for it to even work - or use a clean and disposable browser profile. I've occasionally seen the behavior on the video when I really need to access the page (though usually I just complain to the webmaster).
I once had to request a new password for my online bank account. I ended up asking the bank manager to reset my password, pretending that reCAPTCHA is preventing me from resetting the password myself. My bank is not paying me for solving captchas for Google's benefit (this is so screwed up…).
No, I'm intending to make it hard for sketchy third-party ad companies to track me. Some ad networks can't even avoid serving malware, it's not realistic to expect them to competently safeguard my data.
It just so happens that Google's method for telling if I'm a bot or a human isn't just to show me mangled text, but also to use ad-network-style tracking.
In Google's defence this is probably an attempt to deal with captcha-solving-by-humans-as-a-service or something like that. I can't imagine Google employs many privacy enthusiasts who would spot a problem like this by dogfooding.
You will start getting challenged more often, you'll find you're asked to solve several multi-select challenges in a row even if you get them right, the multi-select challenges will replace tiles after you select them, and the tiles will start fading in and out very slowly.
See https://www.youtube.com/watch?v=en5KSZSpDFY for an example video.
These are (AFAIK) intentional features deployed Google - you just don't see them if they can already track you via something like your Google account.