I tried the audio once. I could hear less than half of the needed numbers. I don't know how blind people are supposed to pass google captchas if the audio challenge is so garbled.
It's because you are using a VPN. You always get a ton more captchas when using a VPN on some websites. Mainly because they don't want you using one, so you can be tracked for ads.
Those are used to train AI, so my guess is there are some kinds of quotas that they have to make within a certain time and when they underperform they just increase the load on each user.
This may have changed since they seem to alter how these things work from time to time, but I’ve found that if you just keep getting one captcha after another, and you know you’re not making errors, try solving them slowly.