The introduction of Manifest V3 API in Chrome for extensions, and disabling Manifest V2 for security reasons. It just so happened that ad blockers were made incompatible with the Manifest V3 API. It's a little blatant considering this came right around the time that YouTube began showing warning messages to users with ad blockers...
Requiring developers to verify their apps via Google Play Developer Console and blocking any unverified APK installations. This is done in such a way that it just so happens to squash F-Droid and most FOSS apps for most people, and blocks any serious competition to Google Play or any apps they don't like.
Of course, there's all this talk about preventing malware, but it is a fact that if you download any random ringtone or PDF app on Google Play it's going to come with probably 25 trackers and send your data to every jurisdiction in the world, and many apps even fail to declare any of this via Google Play data safety or privacy policy. Let's not forget that spyware is a form of malware. Take a look at the leaderboard :) https://reports.exodus-privacy.eu.org/en/reports/list/?filte...
In my opinion, this would probably be an indication that maybe Google controls too much technology and that they may need to be broken up to ensure fair competition. For Christ's sake they almost broke up Microsoft not that long ago for shipping a browser with their operating system, and now Google is blatantly controlling the operating system, the platform and app store, the ecosystem, the browser, the ad network, and abusing their power over it however they can.