Since water-cooled exhaust is also blown by a fan, why is water-cooled stronger than air-cooled?

Firstly, water cooling may not necessarily be stronger than air cooling, but in some (most) cases, it does indeed perform better in terms of heat dissipation than air cooling.
Then, water cooling only makes it easier to carry heat, but the total heat remains constant, so the temperature will eventually increase. That is to say, if a set of water-cooled and air-cooled systems has almost the same total area of heat dissipation fins and air volume, then after a long period of baking, their actual temperature will also be equal.
However, the biggest advantage of water cooling is that it can transport heat in a relatively free space, resulting in theoretically extremely high heat dissipation space.
If it's air-cooled, the highest height of the entire tower should also be controlled at around 17-19cm. The front should not exceed the memory too much, and the back should not exceed the IO part. The upper part should not exceed the height of the motherboard, and the lower part should not affect the graphics card of the first PCIE. With space here, it can only fit so many things of such size, and it is too large and heavy for the motherboard to bear.
And for water cooling, most towers with 240+360 units are fine, and the entire tower starts with a double 360. This is still the case where the cold exhaust is placed. The water pipe is longer, so the cold exhaust can still be placed outside the case. Hey, didn't you expect it? In theory, your home can accommodate up to 48000 units of cold exhaust.

My personal conclusion:
1. Under the same heat dissipation area, water cooling is not as good as air cooling, but water cooling is more likely to accumulate a larger heat dissipation area. By increasing the heat dissipation area, we can achieve surpassing levels.
2. Under the premise of short-term low load use, water cooling is slightly stronger than air cooling because it has a larger heat capacity. However, playing games with continuous load operation will make this advantage disappear.
3. Small area water cooling is not very meaningful, unless you are only adapting to low load operating scenarios.