I don’t think that the current live version of D2R legacy graphics look too bad, definitely not as good as the original with DDraw (my favorite renderer 
) but it looks good enough for me. I mostly just use it to compare the new graphics with the old and sometimes for frame data (I was helping someone figure out the new 2.4 Fury breakpoints).
However, they did made a change in the PTR that completely murders the legacy graphics. Just a horrible, blurry, muddy mess.
Someone made a Reddit post that has pictures, and yeah it just looks horrible. Easier to compare if you open each screenshot in a new tab and swap between them, I hope this change doesn’t make it to live 2.4 but it probably will. 