I believe that "spreading yourself too thin" is a real thing, and a real disadvantage. In a theoretical world, you could have a specific specialization that you

I believe that "spreading yourself too thin" is a real thing, and a real disadvantage. In a theoretical world, you could have a specific specialization that you used in isolation for many different jobs simultaneously, but in reality, a "job" is about so much more than one individual skill. There is onboarding, learning the people and environment and tools and product that you work on, and a variety of other peripheral matters that require much of your time and learning curve before you get to apply the skill you've been hired to perform. And thus you end up with a lot of time spent on things that wouldn't be an issue if you concentrated on one job at a time for a decent period of time.