The simple act of aerating can prevent thatch, improve drainage, increase oxygen and grow a thick healthy lawn.
One major reason to aerate is to relieve soil compaction. Grass growing in compacted or wet or slow draining soil is often invaded by weeds and develops thick thatch. A heavily thatched lawn is deprived of oxygen and won’t allow for good root growth, resulting in grass die off. Drainage will be poor and not allow nutrients to reach the root system.