She probably isn't a perfect tech user, and installed an app that she shouldn't.
But iphone users don't usually have this problem anyway so sister still ends up benefiting from that ecosystem.
Google needs to stay more on top of the app store. It's clear they never had the man power to actually police it well.
There are benefits to that as well, apps that enabled features that carriers didn't want to be enabled used to be pretty popular. Not to mention the benefit of being able to side load apps if you are a power user.
Wait. I've never seen this screen? Are you saying that the play store has a bright red warning like you've described?
I'm talking about the play store, the official store, which has sometimes hosted adware and malware.