Except that when playing chords on a guitar you (1) are fretting multiple notes at the same time, (2) often with your hand and fingers in an awkward position.
This is what I was getting at when I mentioned don't fret too hard. My mind got tricked into thinking I had to fret harder, since I was trying to depress more strings than 1, and due to the awkward positions my hand was in. It is counter intuitive but once you get your fret hand pressure just right, the notes sound better and your hand has less fatigue. You can also move faster around the fret board. This is the same with bass as we all know.