Hi There! 
This is my new Geometry Nodes Assets. It Generate Cayon Rock Formations but it can easilybe modified by given controls parameters to generate different Types of Rock and Formations as well (you'll have to make a diffferent material in that case). 
The Generated mesh is fairly optimized by default and have more density around the edges and leser in the faltter areas and mesh is triangulated.
 
It has 30+ controls parameters easy to use and all are neatly organised in panel in Modiifers Panel with Tooltips Descriptions. there are Acutally two Geometry Nodes Graphs. and Decimate Modifier in Between(there are another Decimate Modifer Disable by default, which can be enabled if less poly count is required). 
The Parameters provide controls over shape, height, thickness, Slope, Smoothness, Noise, Surface, Sub-Formations and much more.
   
Can It be Used/Exported in another Program like Unreal Engine?
Yes, Kinda. but it require some work. there are two way to do that. 
1, Apply the Geometry Nodes Modifier and Baked the Material into PBR Texture. This way you can export you Canyon rock formation into any other program like maya or UE. (less recommended Specially if the desired Application is Unreal Engine.)
2, Just Export The Mehses(after applying Modifiers) without textures and recreate the custom procedural material youself. for UVs use triplanner projection. I am actually storing two extra UVMaps/data in assets so When you export the mesh as .fbx it comes with two extra UV maps, one of which is not a UV map but Edge angles Masks in XY channels (Signed in X, and Unsigned in Y channel) for there use case, and the another UV map is a Cylinder Project, It may not be perfect but its good enough to Use.

Check-out my Other Assets in my: Store
Check-out My Artworks: Abhay Siddhartha