The Google Play Store has long been the bastion for safe and worry-free app downloads
It's nice that the article starts with this blatent lie, so that you know everything that follows is just regurgitating Google's marketing.
Even ignoring that most of the apps in the play store are unreviewed proprietary spyware sending all their data back to Google, there have been many instances of obvious malware being distributed through the play store. It seems like they are trying to sweep that under the rug.
I mean a lot through, but fuck, I would have guessed one order of magnitude lower if you would have made me guess a number. That's a lot of stuff to block. No wonder they don't do human-based reviews, that'd be ~6250 reviews per day, so even if you had 1000 people do nothing but that and assuming normal working schedules, each reviewer would have to review an app every 40 minutes.