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.
Uncut in general. But it can go a bit insane, with a few giant weeds that start turning into bracken. What works for us (but ymmv obvs) is having some dwarf goats or sheep. We move them around the property and they nibble the grass and weeds but don’t make it a miserable mowed lawn. It looks like a lovely meadow. And they’re surprisingly affectionate and relatively low maintence.