Everyone has heard this platitude - which of course, doesn’t make it false. Here’s another way to think about it: Limit your W.I.P. - it’s better to get one little thing done than to have a mountain of unfinished “good intentions” and as soon as you get one thing done, finish the next.
Now, I’m not saying do one thing at a time, but I am saying limit your work in progress such that you are completing tasks in a timely manner. As you complete tasks begin new tasks that are pending. Get into a cadence where you’re delivering value frequently. Actually getting work done makes much more business sense than trying to make yourself (or your department) look like a dragon slayer by taking on too much simultaneous work. If you’re doing everything, you’re likely getting nothing done.