LOD pop-ups and streaming question

I noticed the LODs pop-ins are much heavier in the Denver photogrammetry map than in google earth.
Is this because of a server streaming cap at Cesium or because the streaming solution is not on par with google earth’s yet?

Also noticed that you can walk around in google earth (dl version) now on ground level, which serves as a nice comparison. Their LOD streaming is really smooth. They stream lots of smaller geometries I believe. Maybe that’s the difference.