quads splits into triangles

is there a way to avoid this look without using the smooth funtion? its all quads by the way.

Blender renders only triangles so any quads in your mesh are triangulated at render time. If you have non planar faces then you will see the two triangles unless you use smooth shading.

Use smooth shading or ensure your faces are planar
With smooth shading you can also enable the autosmooth or edge split modifier to maintain the ‘flat’ quad faces

Add a edge split modifier

happy bl

did not fix anything.

They have to be triangles. You can’t possibly have a flat four sided shape that isn’t planar.