Studying is never "useless" :-) Generally, though, there are all kinds of interesting computer science challenges in robotics, ranging from logistics/optimization all the way to heavy DSP/sensing and beyond to AI applications.
The only thing I would recommend against is a PhD. You will not get the time back, and most employers won't pay enough extra to make up for the loss. Many PhDs are also seen as "too narrow" and "not versatile" in general industry (although this is very context specific.) What I've found is that Master's seems to be the "sweet spot," if you actually care about achieving significant progress in industry. (This is as separate from research.)