This changed recently for me, when I got my first 4000 series nvidia gpu, that fucker is huge! And it runs hot, spewing all of its heat directly into the middle of the case. I had serious concerns with this gpu + massive cpu air cooler getting in the way of positive airflow through my case.

And this is where water cooling made perfect sense to me: transport the heat away from the cpu, thus clearing a ton of space from the middle of the case, then have a radiator at the top of the case dissipate that cpu heat.

This allows for a ton of air to go through my case, evacuating all of that heat blowing out of the gpu. This also allows for other heat sinks on the mobo and other components to passively cool better