Is weapon damage enemy level dependent or is an advanced weapon at any level as good as it gets?

If I get an advanced off of a level 50 enemy and one off of a level 75, will the latter do more damage or is advanced just as good as it gets? I have seen people post weapons that do way more damage than my same weapon and am wondering is it enemy level that makes that difference or is it a NG+ thing or both? I am playing on very hard btw. Any input would be appreciated!