Yes your are 100 percent right 3dcn bad geometry is terrible when it comes to organic rigging. So when people create characters they have to be careful especially around the joints.
Yes having multiple renders using wire-frame is a great way to help buyers determine the quality of the geometry.
I noticed that on CGT starting pages only really high quality rendered models show up.
You never see any really cool original low poly or high end game art.
It is nice that they sometimes put up some cool 3D prints but they seem to promote art that is technically great but lacks true originality because it is a perfect reproduction of someone else s work.