Comment by peterfirefly

> One question I have is why have Kelvin sign that is distinct from Latin K and other indistinguishable symbols?

To allow round-tripping.

Unicode did not win by being better than all previously existing encodings, even though it clearly was.

It won by being able to coexist with all those other encodings for years (decades) while the world gradually transitioned. That required the ability to take text in any of those older encodings and transcode it to Unicode and back again without loss (or "gain"!).