So you gave it up not because you are worried about being a "phone addicted zombie" but because you are worried about being precieved and judged as such?

Some would say changing your behaviour due to social insecurity is just another form of being a zombie.

Who cares? They're strangers. If they want to make faulty assumptions and feel an unjustified smug sense of self superiority that's none of my business.

At this point I read ~all books on my phone as a simple matter of practicality. I'd prefer my phone had an epaper screen and grayscale page centric apps (instead of scrolling) but that's just not how things are.