You have identified a major problem.

I never paid attention to the time management gurus, from the 1970s to now. I agree that attention management is now a problem for most people.

I have used a multi-tasking technique for years that is radically different from the normal task-switching ideas presented here.

• I give my brain a problem to solve.
• Go do something else, another task or read sci-fi.
• Go to bed.
• Wake up the next morning with the solution.

There are many ways to solve the same problem.