Not at all. I am more concerned having Facebook (or any other Zuck’s spyware) installed on that very computer. I cannot imagine how anyone would hack my very phone. Also I like to decentralise devices, so none of my devices is a super-device. My go-to phone (iPhone SE with no iOS update, but with security updates) has only a few apps installed that I need for being away from home. My other smartphone (Nexus 6P with no security updates) has loads of apps installed, but I use them only when I need it. The phone has its WiFi, Bluetooth and cellular turned off all of the time. I cannot imagine the way you hack into it, tbh. And even if that would happen, I cannot imagine what a hacker would get out of it, if anything at all.