If it makes you feel better, most labor is useless. In the sense that a computer program and/or machine could easily do it, or the customer could trivially do it themselves. But the labor is cheap enough that having a warm body around is worth it.

We've pretty much locked ourselves into an economic system that requires everyone to work, even though our productivity has skyrocketed many orders of magnitude. The end result is most people are doing meaningless work just because they have to in order to survive, and most jobs do not need to exist. This is true even in office work. It usually manifests as moving stuff from A to B and then maybe back to A. Basically, not creating, just moving. And not physically moving either.