Hi egydes_ceo,

The benefits, you get easy fully support to multiple languages in a website, in all types of text direction, left-to-right, right-to-left and top-to-bottom languages like Japanese, if you using the right logical properties in all places in the CSS file. the only changes you will need is to add direction or writing-mode property.

Example for Japanese:

html{
    writing-mode: vertical-rl;
}

Example for Arabic:

html{
    direction: rtl;
}

all the property will update automatically if logical properties are correct.

I hope it will make more sense to you right now :-)