From what I can find, the original Wipr was released for iOS in Sep 2015 and the macOS version followed in Aug 2018.
Wipr 2 is a complete rewrite and was released in Nov 2024. So, in theory, for £1.99 you could've gotten 9 years of ad-blocking on iOS and for another £1.99 the same on macOS for 6 years.
And since this requires maintenance of the blocklists and associated code, I am totally fine with paying a small amount once every few years. And I'm not even forced to pay as the older versions usually continue to run - albeit on life support.