[angiosperm]

Yet, steam turbines attached to nuke and coal plants spend 10-20% of their time offline, being overhauled mainly because of high-temperature/high-pressure steam's corrosiveness.

Cold distilled water is not corrosive. Superheated steam, howsoever pure, little resembles cold liquid water in any detail. Furthermore, hot water will pick up minerals from whatever it runs through.

Many materials that are not especially corrosive as cold liquids behave quite differently at extreme pressure and temperature. Water has uncommon valuable thermodynamic properties, but not uniquely so; its chief virtue is that it is good enough and cheap.

[pi-e-sigma]

OK, give me an example of one such liquid from your list of 'many' that has all the desired properties of water and doesn't have any undesired, such as being a poison. You can't because there aren't any.