[piskerpan]

62.5% was specifically to bring the default 16px to 10px, which meant now 1em = 10px, at least at the root. With that, you could easily size your entire layout in EMs and, yes, keep it readable:

    .main {
        width: 80em
    }
    .sidebar {
        width: 20em;
    }
    .content {
        width: 60em;
    }

There's no point in bringing the font down to 10px if you're not going to use EMs

[chriswep]

As far as i understand it's about `rem`, not `em` (which is relative to it's parent not the 62.5-normalized root element). And as long as you don't go all-in with absolute units (and loose all control over custom scaling on your site/app), you still need `rem`.

[piskerpan]

The 62.5 hack has been around for a decade before rem was even thought of. The fact that rem would be a better fit for it is irrelevant to the conversation.

I'm just saying that using em and rem for sizing isn't as useful as it once was.

My rule of thumb is to only use them for things directly related to text, like inline icons, text spacing and whatnot.