Yes or no?
One professional philosophy that I’ve tried very hard to embrace is, “be open to the possibility of doing new things or taking on new responsibilities”: a new collaboration, a new side-project, a new outreach activity, a new workshop. In other words, to say, “yes” whenever possible.
I’ve observed a trend towards grad students saying, “I don’t have time”. They spend most of their waking hours working on their research, their papers and their theses: in other words, being good, conscientious students.
I do get why so many grad students balk at doing something new: “new things” almost invariably translate into “more work added to an already stupidly busy student workload”. And while I have no doubt that these students will be great successes academically, I do worry that some of them are letting important professional opportunities slip away.