It’s not Skyrim vs. everything else, it’s older games vs. newer games. Skyrim SE for example also is blurrier than the original Skyrim at the same resolution. Most (almost all) newer games use shader based pseudo antialiasing instead of actual multisampling AA. All these pseudo-AA techniques blur the image, most of them quite heavily.
The only thing you can do about that is disabling post process AA effects like FXAA, TAA, SMAA, MLAA etc. if possible. If you can afford it performance wise, then raise the resolution to get rid of ‘jaggies’. The 1680p quality preset in the vorpX menu usually looks fairly well without any AA. For GTA V that’s probably too much though even for a GTX1080Ti.