It credits Google Play Protect for one of the biggest improvements: its ability to spot extremely harmful apps that commit fraud, steal info or allow hijacks. While there weren't many of them, the mechanism reduced the number of installations by an "order of magnitude" over 2016, Google said. It added that it took down over 250,000 copycat apps (those trying to piggyback off the success of popular apps) and "tens of thousands" of apps violating policies against apps that feature hate speech, illegal acts and porn.
Google is fully aware that its system isn't foolproof, and that some apps will still slip through the cracks. The improvements do make a better case for sticking to Google Play for app downloads when you can, though.
Of course, it's important to stress that this is just one part of the Android security puzzle, and that there are lingering issues that may be difficult or impossible to completely address. Although Google Play Services helps make Protect and other security measures available across a wide range of Android versions, it's still true that most Android phones aren't running recent editions of the operating system. If there's a fix that requires a newer OS, you're stuck.
And remember, many Android users in China and elsewhere don't have access to the Play Store. They have to go through third-party outlets, some of which have poor malware screening. There's only so much Google can do to help when offering the Play Store in China would involve censorship and other compromises, but that still leaves a large chunk of the Android world in a more vulnerable position.