OK, so 20 years before the start of the series, the Ohara Incident happened, and the Gorosei looked the same as they did when they were formally introduced at Jaya.
Now, Vegapunk has been working for the World Government for *at least* 33 years, thanks to the OP Wiki's world timeline. Now, if in this meeting for the cover story, it's been like 35 years and they still look the exact same, we can all agree that these dudes don't age.