tl:dr Yes, you need such apps and more a wholistic approach
Breaking down the possible threats (simplistically) :
1.Viruses: They don't exist on Android. See Is an antivirus really needed for Android?.
malware : Yes a very real threat that is usually piggy backed on apps or users being lured to click spammy links and download payload.
The second one was the preferred vector: we found several news websites that have been hacked by the attackers to redirect visitors to a downloading site that serves malicious APKs
Personally, I find Addons Detector to be reliable for app related threat. But this scans apps after they have been installed so a better approach would be to scan before installing by using Yalp Store which lists all the Play store apps and importantly gives out a report from Exodus scanner (which you also can use directly via its website). Another way of doing pre-install check is submitting the app apk to Virus Total (Thanks to Izzy's suggestion)
Several malware detection apps are available and it is upto your discretion to choose.
- privacy: Apps invading your privacy is another big threat. Apart from choosing open source apps which reduce this possibility, real protection often requires rooting your device, which is not what an average user does.
Tangentially, as one grows old, convenience takes precedence over security and apps can easily invade their privacy (permissions).
- Your second bullet point is highly debatable. You are assuming that Google Play scanning is robust and therefore offers adequate security.
This is simply not true. A Google search for play store apps removed shows at least three instances in last six months when apps were removed from Play Store. One may say that this is evidence of Google tightening security but OTOH your target group of senior citizens may have already been affected! Quoting from one report picked at random to emphasize this
The report also adds that some of the apps dated least a year back and had been downloaded million of times.
Alternative is to install open source apps from f-droid. I do agree that equivalents are not always available but such security apps discussed earlier have a role in supplementing defense.
Choosing open source apps and user education reduces risk partially at least along with selection of right malware apps.
What started as a comment, turned into a long answer (and incomplete). That said, premises of Google Play Protect screening being robust , assuming news websites to be safe or downloading simple games as harmless are not necessarily true as proved often, time and again.
Sourced from Izzy's blog (thanks)