So for example, in the CABG, you have areas of green:
Notice how these form logical planes. You have a plateau and the plateau has stuff growing on it, and then it drops off into cliffs, and there's less stuff on those vertical faces, so they are not green, or green streaked.
This mirrors actual terrain.
The AI doesn't understand that concept though, it's just replicating visual data, so it sees "jagged areas of green" and it makes jagged areas of green:
These don't form planes, because the AI isn't thinking in terms of 3D terrain structure, so you end up with just sort of zigzag bits of green that look like they are growing sideways on the mountain.
Similarly, in the CABG you have water:
The water flows naturally down the 3D terrain in a logical matter. It has a source (the glacial/snow melt at the top), it flows down. Lower down you have additional small sources that also join with the big rivers and flow down. The water forms realistic, smooth rivulets, wnohere is the flow confused, it's easy to read exactly where the water is moving.
In the LBG:
You have confusion. The water doesn't follow obvious logic. Rivers just sort of veer off and dead end, you have rivers that seem to flow sideways and back up. There's no obvious source for the water, because higher up you just have rocky mountains with no apparent snowmelt. Just like the jagged green bits above, the AI sees "blue zigzags" and tries to imitate those blue zigzags, it doesn't think through the 3D logic of water flowing.
You can also see this in the mountain structures:
I hope this communicates what is happening here well, but in the CABG, you have rock arches. These arches are weighted logically. The top parts are thin, and supported by the mountain below. Small bridges between large pillars and peaks.
Compare that with the mountain structures here in the LBG:
Instead of a bridge between two solid foundations, you have basically a mountain peak sitting on top of a bridge, or like a hole put through the middle of a peak. The left bit leans precariously sidewise, so the entire structure feels unbalanced with the weight high instead of low, and it comes across like less realistic terrain.
Also note that the CABG has actual details.
Individual trees, individual stalactites, unique bits of hilltop. The LBG just has confused colors. It's like blocking in the general shapes, but never actually taking the time to go in and draw the individual terrain features that make a thing feel detailed. It comes across more like a bunch of areas of maybe-jungle-maybe-lichen-vague-green rather than fields and pine forests and lone trees.