People not getting OS security updates anymore is a serious problem anyway. No matter if Bitcoin or traditional finance.
Be sure that all of those twitter bots and a sgnificant chunk of all likes on Instagram are just bots on old Android phones. We have not seen a mass theft of Bitcoin wallets worldwide. This is probably due to ARM chips having secure enclaves which are really hard to crack even when you already have malware on the victim.
Pray to God that we never see a headline about such a hack. And that free ROMs become really mainstream before that happens. And that Samsung/OnePlus/Sony deliver phones with 10 years of security updates soon. Otherwise the third world will be at a serious disadvantage.