I do this all the time. Hold your kindle or book far enough away that you have good peripheral vision of your surroundings. Practice widening your view so you can use your peripheral vision to guide your steps while you walk. Look up at intersections.

I can only do this with books. With my phone I am too focused on the phone to work in two visual modes at the same time, which I guess supports the claims.

For a while, I programmed while walking on a mini-laptop. Nice walking paths where I lived. I was on a hobby project and wanted to spend any minute on it. It wasn't pretty. I kept trying to design a contraption I could wear on my shoulders that worked like a laptop desk.

I also attached a laptop to a treadmill at home, but the static electricity from the rubber mat kept zapping the laptop.

The best result was a laptop on an exercise bike. But the bike couldn't have a high resistance or I would lose concentration.

In my city, if the area is so crowded I can pick a stranger to follow to the common destination or if it's so empty that I don't have to worry about walking into someone, I can confidently read even the most engrossing novel on my phone. I won't dare doing that with any bigger screen because I won't be able to see the upcoming obstacle.

Read while walking, I live in a walkable city. The pedestrian way is safe. I stop reading when I arrive at any intersection then start again once I cross. Even as a kid, I'd rush to open any magazine I bought before I got back home and would read them while walking.

Reading while walking is possible. I used to do this. But with physical books