Call me cynical, but from the comments online, I think this research is being used for propaganda marketing to push for MV3 adoption - to assuage the lay users that all the hue and cry is for nothing and they shouldn't abandon Chrome, and to provide an excuse for other browsers holding out to embrace MV3 completely. (Don't be surprised if Firefox suddenly changes its mind and decides to fully embrace MV3 and drop MV2).
Here is the actual research - Privacy vs. Profit: The Impact of Google's Manifest Version 3 (MV3) Update on Ad Blocker Effectiveness - https://arxiv.org/html/2503.01000v2
> This study comes with several limitations ... this study faces limitations related to the dynamic behavior of websites and extensions ... Second, consistent with previous research, the automated browser-based experiment does not replicate all aspects of user interactions, such as visiting sub-pages of a website’s homepage, which introduce different trackers than the website’s homepage ... Third, the study explores ad blocker effectiveness using a European IP address and default ad blocker settings on a select sample of websites, focusing on display ads. As a result, the web’s long tail is under-represented. Consequently, we cannot rule out that MV3’s 30,000-rule limit could disproportionately affect less popular websites that rely on rarely used rule ... Because EU traffic often involves GDPR-driven website changes that reduce third-party activity irrespective of consent, baseline ad and tracker counts are lower ... Fourth, our study cannot exclude that any future changes to the Chrome extension ecosystem might hinder ad blocker effectiveness, as feared by some ad blocker providers ...
Note that the intent of this study was to determine if MV3 ad-blockers are as effective as MV2 based ad-blockers. Nobody has said that MV3 cannot be used to block ads or trackers. What they have always criticised is that it makes it harder to do so than MV2, and the difficulty of implementing dynamic filtering with it gives the advertisers an upper hand over adblockers.
When the ad-block extension developers tell you that MV3 cripples their extension and makes it harder to block ads and trackers in your browser, who are you going to believe - the experts at blocking ads and trackers or a corporate who makes its money from data harvesting and online advertising and has a real incentive to cripple ad-blocking on browsers?