I don’t think they are things that can be fixed on the app level?
Indeed not. So I’m trying to better understand how vulnerabilities at the system level are exploited. It seems like the attack surface is limited to RF (bluetooth/wifi can be turned off if one is willing to make that compromise), app install (many just use a small selection of well-trusted apps), and messaging/browser which are regularly updated if the device is properly configured.
Based on this thread I’m beginning to form the opinion that it is not unreasonably foolhardy for someone to continue to use an unsupported device if they are willing to make the compromises necessary to limit their attack surface.