I know why water was chosen. Brine also has characteristics that are useful. My point was that it's just one (specific version of a) molecule at one specific altitude, and pressure varies, so there is no true "sea level pressure". It is not a concrete thing where zero means zero.

Metric I love. C is not metric though. It's an SI unit, but not metric, as often as those are conflated. It doesn't have any fundamental advantage over F.

I'm not arguing for K over C. I'm arguing that C and F are both fine. People acting like C is fundamentally better are mistaken. They're both just setting 0 as some useful value that we can still go below.

0 (least water movement) to 100 (most water movement)

Temperature is a measure of movement. If we can continue to lower or raise the temperature, these are not the lowest or highest values for movement.

And people arguing for C because it's metric are just wrong, because it isn't metric. It's frequently used by the same people who use the metric system, but it isn't metric. The metric unit for temperature is K.

I agree that K is impractical. C and F have far more utility in everyday life. In my opinion, they're both fine. For cooking, I tend to think in C. For weather, I tend to think in F. They're both just arbitrary choosing useful values, and this means they're both useful for different things.