> Once people install ad blockers, they don't typically remove them. And ad-blockers keep growing
> don't fundamentally understand why people allow ads on their devices when they can prevent it
The market share of iOS also has increased a bit, and iOS does not allow ad blocking very easily. You have to configure some sorta DNS-based ad blocking, which is harder than the traditional desktop firefox/chrome adblockers to install.
Usage of computers has also shifted towards phone/tablet apps, away from desktop browsers... And ad-blocking in apps is hard to impossible compared to on desktops.
I'm not surprised people continue to see a lot of ads as we move from the web, where mature ad-blockers exist, to apps, where ad-blocking is harder and less mature.
Even very technical people usually don't bother with pi-hole and see ads in free android apps.
Oh, and also, there are occasionally cases of an ad-blocker removing itself somewhat, i.e. adblock plus used to be the go to recommendation for ad-blocking, but they started allowing google ads through in an update (https://adblockplus.org/en/acceptable-ads)... so maybe someone installed adblock plus because that's what they remembered from 10 years ago (and adblock plus has better SEO than ublock origin too), and thus still gets google ads now.