Google which is android creator, should intervene and remove it at all costs because its in their best intrest to keep android semi-secure.
Google as the owner of Android OS can only make some security improvements, but it cannot affect the way users install apps on their smartphones. If their service Google Play is the source of the infection (and in most cases this is true), they should check any app before approval, and that is not something they want/can do at that time.
I am quite scared of the (lack of) security mobile phones offer nowadays. I use a 3rd party antivirus for checking the things I install, but I am aware that some things can easily hidden from antiviruses too.
The phone you had in hand was rooted or not? I hope that only rooted phones are affected...
I can only say that that phone is got this infection after owner is downloaded some sport-related app from Google Play, but I am not sure is phone rooted or not. What I can say that it was a phone without any protection and no updates from Google in the last 2 years.
xHelper is not a new type of malware, and many antivirus software has protection from that threat, but removal from the infected device is a big problem since malware is adapting.
What I found on the page from Symantec is that this malware is possible targeting Jio 4G network users in India, who already have a free app that protects them from xHelper.
Symantec - xHelper