Water cooling is needed when you have high ambient temps like living in a hot place without AC.
Incorrect. Explain how this is true? Both air and liquid cooling both have to dissipate the same thermal wattage in any ambient temperature range. Liquid cooling is just more efficient in removing the heat load from the component producing it. It still requires ambient air to exchange into the ambient atmosphere, just like air cooling.
Also if you are extremely overclocking you might have about 5% better results on average with better cooling from my experience.
This varies widely depending on BIOS setup, hardware chosen, quality or binning of hardware, but could allow for a higher stable overclock in some instances, assuming the liquid cooling solution has adequate efficiency headroom over air cooling.
I switched back to air cooling long time ago as it provided no benefit for me, I am in Canada and its cold here, I have AC in the short summer. With water cooling you have the hassle of maintaining it and there is a chance of leakage which can damage components.
1) There isn't any indication whether the OP of the thread meant custom watercooling or AIO cooling. 'Liquid cooling' is mentioned, which makes me think it is meant to be AIO, which does not require coolant maintenance...only dust/debris maintenance of the fans and radiator.
2) If someone feels that flushing a watercooling system is a hassle or too much work, then it is likely that custom watercooling really isn't for them.
3) We should identify the differences of AIO/custom watercooling and determine what the thread is wishing to pursue (if any). This prevents misunderstandings.