When Multitasking Makes You Happy and When It Doesn’t (hbr.org)

Any decent boss should now this. Make sure your people, especially knowledge workers, have several projects going. Sometimes you need to work on something and then set it down for a while. But that doesn't mean you stop coming into work. You just work on something else.

Lol. TL;DR It doesn't, unless you change modern English and count working in hour long blocks 'multitasking'