Physical properties of water are much better than the properties of air. Actually the specific heat capacity of water is better than that of any other fluid or gas on earth. Water transfers heat more efficiently because of this.
Using a high flow rate of coolant through an efficient water block will beat any air cooler.
One litre of water can bring about 3000 times more energy out from a system when compared with one litre of air. This comes from the physical properties of air: it’s heat conductivity is poor.
In order to cool well Air
All this increases the air resistance, increases the blow pressure and thus power needed. As a result the cooling power of watercooling is superior to air cooling.
Water cooling has also a small Footprint