It is not like that for everyone. It depends on the kind of browser and VPN you are using. The more private your connection is the more captchas you may likely solve.
I am seeing it on three different browsers and only Duckduckgo is a bit private, the other two browsers are not.
I have experienced that sometimes too and from my experience I think it mostly happens when the forum traffic is way high. But sometimes the strength of our internet connection can also be a contributing factor.