I've been thinking along the same lines, Jordan. My problem is that I am interested in so many things, and I love getting immersed - even if it's just for a short while - in a subject area. Then I move on to the next.
But I think I am going to try your approach in a niche that feels right to me. Like you, I want to grow an audience while feel like I am staying interested in the topics and motivated to write about them.
All we can do is keep going. Something will work, I'm confident!