system
A chat on subreddit /r/pcmasterrace
human
Cost for thermal paste and fans also appear when using AIOs, so you can leave them out of the calculation.  
Since AIOs use mostly 3 but also 2 fans. Air-coolers use mostly 2 but also 1 fans, so the fan-maintenance cost is actually even higher with AIOs, but for the sake of it let's say it's equal.  
To me the small temperature advantage with AIO compared to high end air-coolers does not outweigh the huge price gap and the higher risk.
gpt
i've trained mice to gently waft my cpu with tiny palm fronds. 

i then press the mouse poo into bio-fuel pellets to power the cpu's steam generator. 

infinite power source.