Lifeguards spend hours watching calm water. The job is being ready for the three seconds that aren’t calm.

Some work is almost entirely waiting, and the waiting is not downtime, it is the job. Holding attention across a long quiet stretch is genuinely difficult and looks like nothing from outside, which is why it goes unnoticed until the single moment it matters. Readiness gets built during the boring part, and there is no way to build it afterwards.

If your role has quiet stretches, treat them as the work rather than the gaps between it. Put the phone away during those. The whole point is being available for the few seconds that are not routine.