There is a new Cesium blog post by Dan about the Logarithmic Depth Buffer CesiumJS now uses under-the-hood to avoid z-fighting with massive view distances:
This is a rare win-win case where both the performance and visual quality are now better. The performance improved because duplicate draw commands were eliminated for most pragmatic cases. Visual quality improved since multi-frustum overlap artifacts are generally eliminated and the default near plane distant is now 0.1 meter (it was previously 1m) so you can zoom in very close, which is especially useful for indoor scenes. Previously, a closer near plane would have had a greater impact on performance.
For more details, check out the blog post.