I personally think uncut is better as it looks more natural, and is probably better for bees and other insects. The flowers and other weeds that grow make it look nicer as well.
I don’t think cutting a lawn is that bad as long as its not done too often, though.
edit: grass. This is a post about grass.
Edit: Lawns, like the grass in your lawn, jesus christ.
Pretty sure straight up grass is not all that great for most critters regardless. I know some folks mention that all clover is actually decent since it doesn’t grow all that high and is still good for insect life.