There’s a point. Usually it’s to stroke the ego of the managers and reinforce that they can make you do anything, regardless of how useless that activity is.
They can also spend the time interrogating everyone at the same time about how their output isn’t good enough and that they should try harder despite having most of their working time being sucked up with unproductive meetings and fucking TPS reports, and filling out time and completion information on their tracking system, all while you’re getting random ad-hoc untracked walk-up requests from anyone passing by.
I swear, I spend more time reporting and accounting for the fact that yes, I’m working, like I’m paid to do, and I’m expected to do, than I actually spend on doing the work I’ve been hired for. Now we have mandatory meetings about whether I’m doing work and why I’m so far behind and/or so slow at getting things done… maybe I’d be able to get my work finished faster if I didn’t have to stop every 10 minutes to report that, yes, I’m actually still working on the tasks I’m assigned, and dealing with Mark for the sixth time today because he walks by my desk and always has some inane complaint/request/question that he just needs to relay to me every time he goes to the bathroom. I’m not your therapist Mark, if you need me to do something, submit it through the tracking system so I don’t keep looking like a lazy-assed failure! But no, mark is the step nephew of some c-level and if I actually complain or deny him, he’s going to run off to my superior and then I’m going to have more meetings and shit on my plate. I just want to do my job. Leave me the fuck alone.
If your boss is checking in on you that much, that isn’t a good sign.
At minimum, I would let your boss know before you do anything for the nephew because it is their job to say your priorities. Hell, you can even blame your boss for doing this. “I’m sorry, but my boss won’t let me do that” is a great excuse which puts the responsibility on someone else.