Hi,
to solve this issue please provide screenshot of your reconstruction texture settings. I think you are looking at simplified reconstruction used for Sketchfab so the resulting quality of the model is simplified. However the main issue here is the quality of your texture generated.
Here is a orthophographic manual: https://support.capturingreality.com/hc/en-us/articles/115002328751-Orthographic-projections-in-RealityCapture
To export this ortho you have to set BigTIFF option because it’s too big for ordinary Tiff.
It is not possible to view model with more than 40M triangles in RC. The Sketchfab model is also simplified and you need Pro account if you wish to upload better quality model there.
Michal