Yes. I believe it helps with motivation, which for some people, like myself for example, is often the bottleneck of productivity.
Off course, others may have more intrinsic motivation, or just more discipline.
But if you are lazy like me, it helps a lot. Whenever i reach that point, i get into a zone, and just keep going and going. Im not working better, or more effectively, im just more motivated, and end up investing more time and effort.
The feeling of gettings things done motivates. Even when that feeling is an illusion.
So what if it actually took 4 hours: if it feels like 30 minute, its easy to invest another "30 minutes".