i love this idea that water is completely irrelevant to humans, as if it's not like 60% of our mass and vital to living

yeah no let's base the temperature scale around what some english dude felt was comfortable

I could be wrong on this, but I think Kelvin is basically required for thermodynamic measurements. Entropy measurements, for example, depend on ratios between temperatures relative to absolute zero. You could still manage using centigrade of course, but you would have to offset all of your temperature measurements by 273.15

Probably a lot of other physical applications that also depend on having an absolute zero reference, but that's the only one I can think of for now.

The freezing point of water is also a great place to zero the scale

I disagree. Realistically the scale shouldn't be able to be negative at all. It doesn't really make any sense for something have a negative temperature.

Imagine if other scales worked that way. An object can't be negative centimeters long. Light can't be negative lumens. You can't score negative % on a test. If you are measuring something you can't have less than nothing.

Plus 100 is boiling it's a perfect scale.