To stop scammer-guided malware installation, and probably those "download whatsappupdate.apk for free new emoji" ads that pop up all the time.

Google doesn't care about F-Droid one way or the other. It's a niche project that barely registers on the scale of all Android users.

F-Droid still works the same as it did before. This just means that McDonald's can distribute its apps on its website without showing a scary warning on install on Google's Android builds.

To defeat scammers. Not everything is a conspiracy.