That’s not my model, and I have no control of what they did with their content. Also, it is avoidable.
Which is why I said “almost”.
No offense, but this is getting ridiculous. Google “edge flow”.
The reason why it is a good idea to use quads in modeling program, because it will allow you to use more powerful tools and subdivide model easily during modeling phase. Not because of “performance”. Triangles will cause a mess when subdivision is involved and edge loop tools won’t properly work on them. “Edge loop tools” means that you can click one edge on the arm, it will select the whole circle that goes around the arm, and you’ll be able to scale/move/rotate it, dissolve it (remove edges, while preserving geometry), and slide it up and down across surface of nearest polygons. That is not gonna work with triangles.
While GPU does render everything using triangles, that is not relevant to the issue.
Frankly, just model a high-poly human surface (human head, armor, etc), and you’ll see it yourself.