I read an article years ago by a man who run a lawn service in New Zealand that looked after special lawns like golf courses. He gave some tips.

One of his tips was to see the grass as small tree’s that had a top and root system that had a trunk. He said that of the top of the grass is cut off them the light would get in and dry the grass around the roots and the lawn would die.
His recommendation was that the lawn should never be cut low, especially in Summertime.

He wrote that it was better to more the lawn at the top, imagine the tree and you trim the tree, but still leave enough of the canopy left to allow for the shade to remain around the roots of the grass.

This allows the grass to mostly remain green, healthy, and the roots shaded and also stops the ground around the grass to remain moist longer.

Some people get caught into that rut where they mow the lawns too low, the lawns die, and then they cannot understand what is wrong, so they add nutrients, water the lawns, and yet the grass is always dying – and this is because the lawn is cut too low.