Building their own coffin
Google's failure to sort out Android security is well known. I can see the practical and commercial reasons for doing nothing for handsets that have been remaindered, and at the moment this malware is in the badlands outside the Play store. But you can see where this is heading.
Unfortunately for Google, their failure to fully secure up even the current version, never mind the billions of older devices means that sooner or later something really nasty is going to make it into the Play store, and all hell will be let loose across millions of phones - be it ransomware, some form of APT or botnet, keylogging/bank spying, or whatever. And when that happens, Apple's cash registers will melt, as a significant proportion of people decide that whilst they don't mind Google spying on them, they simply won't tolerate its slipshod security, and indifference to older handsets.
Personally I don't own any Apple products, and I don't like their obscene profits and limited user control. But I can see the day coming when Android is less a phone OS, and more of a malware deployment system.