Back in the days of 20th century ambitious, well-funded journalism, it was common to see specialized writers do their boldest, most imaginative work in their first year on the beat.
They also made some newbie mistakes, but on their good days, they saw stuff that the old pros didn't. They asked the "obvious" questions that everyone else had stopped asking. They ventured into areas that according to conventional wisdom were "unimportant" or "not yet significant."
People who had been on the same beat for 10 years or more could reliably generate solid and perhaps even admired work in their specialties. But they worked within shrinking boundaries.
The senior editors who really earned their keep made sure that the rest of us kept rotating into new fields every few years, so that the "wow!" factor never left our work.