"The phone's the problem, not the podcast"
Some readers will feel that this book has the wrong target. The phone is the problem, everyone knows that, and there's an earlier book in this series about it. A podcast on a walk is a different thing. It's wholesome. It's what people did with the radio for a century.
I'd agree that the phone is worse in some ways, and the earlier book says why. One study it uses is worth borrowing. Dora and colleagues, in 2021, had eighty-three PhD students rate their tiredness and boredom hourly for a period while their phone use was logged. People were more likely to pick up the phone when they were tired or bored, and they reported more tiredness and boredom afterwards, not less. The phone answered boredom and produced more of it. That study was small and exploratory and about phones, and I wouldn't carry its numbers to a podcast.
But look at what's common to the phone and the podcast. Both go into a quiet minute by default. Both take the attention that the quiet minute would have had. Both prevent the drift, the sorting and the incubation that chapters 4, 5 and 8 described. The phone does it with more churn and the podcast with more content, and the podcast is better company, and neither leaves the minute empty. The habit this book is about isn't the phone. It's the filling, and a life in which every minute has a wholesome podcast in it is exactly as full as one in which every minute has a feed, and has exactly as little room in it for anything to form.
There's a way the podcast is harder to give up than the phone, and it's worth naming. The phone feels like a vice, so people are ready to hear that it costs something. The podcast feels like a virtue, and chapter 5 was about why that feeling protects it. Nobody's ashamed of listening to history on the way to work, and so nobody asks what the history is displacing.
So keep the podcast, and keep the distinction, and apply the method to both. The earlier book has the arrangements for the phone. This one has the arrangements for everything that goes into a quiet minute, and the podcast is on the list, not because it's bad, but because it's there.