The Agisoft Metashape Professional manual states that the 'most accurate' dem is created using the dense point cloud. Below is a screen shot from the manual with the relevant text underlined. Also, the manual states that the mesh is constructed from the point cloud which would seem like another step.
Also, there is this from the Building DEMs and Parameters section of the Metashape manual.
Given that the DEM is better from the dense point cloud it would follow that the ortho would also be better.
There is one benefit to the mesh generated ortho in that you can use that image for facades of buildings and such.
