See, I disagree that metric is a more human scale because there's nothing special to me about the temperatures 0 or 100 in it. Like, 0 is really cold to me (I hate being cold haha), but there's no reason to specifically care that the temperature is 0 fahrenheit and not 10 Fahrenheit or -5 Fahrenheit (also really cold to me). Likewise, 100 F is hot, but there's nothing in my mind special about how hot that temperature is. Whereas, there's something I can do with the information that the temperature is 0 C, because I know water freezes at that temperature. And that's really useful to know! And I know that I can boil water (at sea level) at 100 C. 100 C seems like it should be a really hot temperature, and indeed in Celsius it is really, really hot and a human could not survive for any significant length of time at that temperature. But they can also use it to do something functionally useful to them. So I think Celsius is a human unit because the number choices are exceedingly useful on a human scale. This is opposed to Kelvin, which has absolute zero as 0 K, which I would agree is not a human scale of temperatures in any fashion. But no one uses Kelvin for weather or most daily life applications for precisely that reason.

And yes, conversion factors are a huge reason for why I love metric. Also the fact that the conversion factors are built into the prefix names. I love that too!