There is a doom loop mode where it doesn't matter how many you solve or even if you get them correct. My source for this works on this product at Google.
I know it's still not justified, but it's the easy solution that works for preventing DOS attacks.
Kinda wild that someone scraping google's data would prevent me from getting into my PAID (>90$/yr) Dropbox account. That experience is a big part of why I pay extra to host my host data on my own server now.
Decentralization, hosting your own stuff, is great until you run into DDOS attacks and have to make maintaining your server a full time job. Sure you have the skills (or can acquire it), but do you have the time ?
What is the purpose of such loop? Bots can simply switch to another residential proxy when the captcha success rate gets low. For normal humans, it is literally "computer says no".