The now-standard metaphor of attention as a scarce resource — something to be spent, budgeted, guarded from theft — gets the shape of the problem roughly right and the mechanism almost entirely wrong, and I think the wrongness has practical consequences for how people try to fix their own attention.
A resource, once spent, is simply gone; the metaphor implies that if you just avoid spending attention on the wrong things, you’ll have more left for the right ones, like money saved rather than blown. But attention behaves less like a fixed budget and more like a muscle that also happens to be a habit — the more it’s spent in short, interrupted bursts, the worse it gets at spending itself in long ones, independent of how much ‘total’ attention was theoretically available that day. Cutting the bad expenditures doesn’t automatically refill a reserve. It just leaves you with an under-trained capacity for the long kind, which is a different and worse problem than running low on a fund.
This is why the advice that follows from the resource metaphor — block the distracting apps, protect the calendar — helps less than it should for a lot of people who try it and still can’t sit with one piece of writing for ninety minutes. The blocking solves a leak. It doesn’t retrain the muscle that atrophied while the leak was open, which needs the boring, unglamorous work of practicing long unbroken stretches, not just defending against short ones.