In my experience this is absolutely wrong. Context switching is one of those essentials that you cannot cheat or improve upon. It’s like assuming that if I walk to work often enough, eventually it won’t burn any calories because I got so good at it.

The issue of filling waiting time is understandable, but recognizing the cost of switching to various tasks can still be useful in determining how to fill your time. Something that doesn’t take you out of what you were already doing will always be better than something completely unrelated and possibly information-loaded.