Yeah, it's not likely if you're really careful. But as I said, most people aren't careful. I don't mean us LUG guys - we're pretty careful.
An AV is just that extra level of protection although I wasn't aware of Play Protect and how it works. That may be enough. Still, I use AVG Antivirus on my phone. Call me super paranoid :-) I just have the free version though and so far I haven't noticed it consuming very many resources. Maybe it doesn't actually do anything

Just kidding. It does have a some cool features if you have the Pro version like taking the picture of the first person to try to access your phone and fail and tracking when it's stolen and some cleanup utilities. Your mileage may vary.
But as the article says, there's no reason to panic every time we hear about new malware apps.