Rendered image looks pixelated

Hi everyone,

i am using this .obj file: https://unblast.com/free-apple-watch-series-5-3d-model-max/

The 3D model was originally created in 3Ds MAX. I can easily import the .obj file in dimension and also assign materials. But when I render the image, it looks like this, even though the resolution is 2048x2048px:

Of course I set the render quality to high

Why does the result look so bad compared to the original rendered image with 3Ds MAX?

What am I doing wrong? How can I improve the result?

I haven't changed my scene. All standard.

Thanks for your answer