Ironically, it was the walled garden that kept me on Apple for so long. Having at least the illusion that apps were safe and secure gave me some confidence that most of the apps are reasonably safe does remove stress and means I don't have to vet things too closely. In truth there are nasties in the Apple world too, but I'm sure it's nowhere near as wild as installing random .apk files.
What made me leave Apple was for a real headphone socket, an SD card slot, and especially USB-C charging. Those were the non-negotiables for me.