Granted, it was in the Stone Age…but when it applied to grad school, my work experience and LOR were what mattered. I don’t think there was even a space for ECs on the application, and that included the fellowship applications.
For my older kid, his grad school applications were solely dependent on his talent…ECs on’y mattered if they were things like winning music competitions.
For my younger kid, that kid took 5 years between undergrad and professional school. What she did during those five years mattered. Not ECs…I mean she had some, but I don’t think they were even mentioned on her applications (things like community orchestra).