Why does `placeholder-shown:no-underline` work but `placeholder:no-underline` doesn't?

I expected placeholder:no-underline to remove the underline of an input's placeholder. However, placeholder-shown:no-underline does work. But I don't understand the CSS that is being created. Why does one work and the other not?


Example:

https://play.tailwindcss.com/gZIVyRDi6y