> You can't use an en dash as a 'dash'.

Actually you can, and it's relatively common.

One way—like this—is to use em dashes without surrounding spaces, to denote a pause.

The other way – like this – is to use en dashes with surrounding spaces. This functions like an em dash, but is technically an en dash. The linked article has dashes like this throughout. (Then you still use an en dash for numbers like 11–13, but without the spaces.)

It's just two different typographical conventions.

Edit: to be clear, these are both still different from hyphens. In typesetting, don't ever do this-or this - as hyphens are for, well, hyphenation.