Doesn't it require jumping through a ton of hoops to install apks from unknown sources on modern Android? How many people are A) capable of doing this, and B) naive enough to actually do it?
That said, I don't use Chrome so I've never seen that incredibly shady-looking real update notification they showed in the article. If Google has indeed trained users to expect and accept something like that, then shame on Google. I can't blame users for thinking the fake one is legit. It looks very similar (and it seems like it would be trivial to make it look 100% identical). But still, how does the apk actually get installed?