Despite the developers and their company's attempts to invade our lives, the fact is the smartphone is just a tool. Like TV, or pot, it can enrich our lives or worsen it depending on how we use it.
I think that as long as we do have agency and retain awareness of our choice, then it is worth using a smartphone still.
The thing is, for many younger people raised on this tech, there may be no going back. Their sense of self, their manner of dealing with the world will be different, but given augmented reality, smart devices and so forth, their inter-subjective selves may exist on a completely different scale which can be both astonishing, enriching and -to those of us raised before the predominance of social media - completely frightening.
My point (I think) is that as long as people born before 2005-ish retain an awareness of a choice not to use our smart phones then we can just be ourselves, same as ever. For younger folks, even if they can't live without a phone, I think they will find a way to be themselves, and that isn't necessarily a bad thing. They will just have to learn a different way of considering things.