It frustrates me when I see people doing something that requires MORE effort, but looks worse.

If you want to refer to a range of dates, you write it like 1927–1933, using an en dash with no spaces around it.

But yesterday I saw someone write it as 1927 — 1933. It looks wrong. It uses an em dash (which is too long), and there are spaces on either side. This is harder to read, because the years are closer to the words around them than to the other year.