What's wrong with using react-router? That's just one solution that I've found easy and without significant limitation. Easier than native solutions. I'm predominantly a web developer who uses React and related technologies a lot, which makes me wonder if many of the people who are frustrated with RN aren't exactly the target audience and will hit a learning curve.
Core navigation still doesn't "just work" for RN. At all. The pure JS solutions are garbage and limit what you can do tremendously. The native solutions have tons of other issues you have to hack around.