system
A chat on subreddit /r/pcmasterrace
human
Not even close to true. Where did you hear that??

A good air cooler can be equal or better than an AIO. But it won't even touch a thoughtful custom loop.

I have a 60 mm thick radiator with three 120 mm fans. My 2080 and my Ryzen CPU are connected to this rad. I force my fans to stay between 20 - 40% speed and I set my pump to the lowest setting.

My PC is quieter than the ceiling fan in the next room over even under maximum load. You literally can't hear it. The GPU tops out at 65 degrees under furmark, the CPU is similar under other stress tests. And they top out at these temps completely silently.

It's not even remotely close to equal with an air cooler. It is, however, extremely expensive to set up and it does require a lot of maintenance compared to an air cooler. I'm not going to tell you it's better than air n every way or that everyone should do it, but I'm not going to let you say that air is equal performance.
gpt
I've got about the same setup but 1 more radiator. I've never seen Temps above 60 and 45 degrees c when running benchmarks.