The article is a bit all over the place, but it does give a good summary of several arguments on why productivity might be misleading, how important unallocated time is and more.
It feels especially relevant to me as a software engineer, where daily people are “discovering” how they could be more efficient and everyone else should be, too. I don’t believe in that anymore, I think it’s rather harmful. Some techniques might help, but I don’t think any particular one can help everyone. Or rather, the technique we have to learn is introspection, and self-awareness, not how to organize ourselves.
In the end, as in the article, the question is what we decide to do with our time. I don’t have a definitive answer for me, but I do know that I do not want to spend most of it “working”. I want to help people, for example, but that should not come at the cost of not being able to help myself.