Earlier quoted context omitted.
All true, but neither should we deny ourselves a long session of "flow" if it makes us happy.
I'm finding that 'flow' is a significant contributor to NIH Syndrome. You can't flow while integrating a third party library anywhere near as easily as you can flow by rewriting half of it (badly) from scratch. Flow is a rush. Anything that is a rush can be indulged in to the point of self- (or other-) harm.
I frequently need to reach states of deep flow when I am reading large inter-related files for refactoring, or modifying existing code to use a new library, or to follow tutorials for something only tangential, like new deployment tooling.
Reaching states of flow is necessary no matter what you’re doing, and given the insane explosion of modern process overhead and meeting-centric corporate culture, it’s important to protect flow time and make it known how important flow is. Whereas I can see how people might try to use thinking like in your comment to undermine flow time, and falsely act like it’s somehow better to deny developers workspace or blocks of time for getting into flow states.