I thought this as well until I had to use a "widget library" that used REM to style.
If i set the HTML font-size to 16px (the default) the widgets are WAY too big, if it set it to 10px (what they use in their examples) it looks great but everything else is too small.
So I need to either re-style all the widgets (damn near impossible), or set all other elements to 1.6rem...
If they used em, i could just set the container to what I wanted and called it a day.
So em definitely has it's place, but I think the majority misuse it.
If i set the HTML font-size to 16px (the default) the widgets are WAY too big, if it set it to 10px (what they use in their examples) it looks great but everything else is too small.
So I need to either re-style all the widgets (damn near impossible), or set all other elements to 1.6rem...
If they used em, i could just set the container to what I wanted and called it a day.
So em definitely has it's place, but I think the majority misuse it.