Now it’s more easy to observe how each Roblox Part has multiple edges on each face, without a very serious reason as to why in my opinion, except legacy.
Back in the day, all parts had a smooth edge to them. This was later reduced to just an outline, and now parts are flat and smooth in visuals. In reality, the edge is still there, which compared to importing meshes from Blender or programs like this, will lag the game more in large quantities.
Until observing this, the myth of meshes lagging less most of the time seemed something made up than objective. Now I really believe in this.