From a technical perspective, upsampling reduces display-based image degradation and, correctly implemented, it equalizes the spatial frequency response across the sensitivity range (e.g. it removes image degradation due to optics and electronic sampling. ) Server side whole-image processing outperforms simple display side interpolation in this respect. To show this effect, consider below a detail from our first image. Here is the image again:
And here is a detail, showing the original data at left, Aqueti 3x upsampled data in the center and bilinear 3x interpolation at right. The additional sharpening in the Aqueti data is essential to getting the best true estimate of the upsampled data and is only possible with more aggressive processing.
Similarly, we consider details from the 3x upsampled version of this image: