Knowing more doesn’t mean saying more. Often it means saying less, actually.
First, you say less because you know more efficient ways to say things. Why use ten words when you could use five? (My mentor used to say to some students on the podium, “Talk less, say more.”)
Second, you say less because you’ve learned the most effective things to say to get the outcomes you’re seeking. I find that the things most important to me need repeating, and I find myself going back to them again and again, rather than always covering new ground with my ensembles. In my first rehearsal with Shades of Blue yesterday, I leaned on several things that returning members have probably heard countless times.
That’s a feature, not a bug. I know more, than I did when I started my career, and I say less because I’ve better learned what to say to get the job done.