Modder zomprd is upscaling parts of Diablo 2 and will eventually release a demo that includes parts of the game playable with sharp graphics. These HQ textures were generated using ESRGAN and look much blurrier than the original maximum resolution of 800 x 600.

Unfortunately, zomprd is not currently working on a full texture pack for Diablo 2, but they are hoping that by releasing a playable demo of a portion of it, they may be able to inspire others who can make a full pack. That would be nice.

You can see a gallery of zomprd's work on imgur. It certainly doesn't look like a before image of an ad for a new pair of glasses.