I dislike it, too. But I add it, because we have managers who do check their email on days off & respond. That’s above my pay grade as far as I’m concerned, but I don’t want people to think that I might be checking.
With all that in mind, read on for a few examples of what you might actually write...

I dunno, this is one of those areas I feel like people overanalyze. Like, yes, there are definitely some away messages that make me raise an eyebrow and I really don’t want anyone’s medical history. I’m not a huge fan of the one from the LW cause it’s a bit cutesy and takes too long to get to the point — I prefer short and sweet. But some people also just…struggle with how to put together an away message and copy what their boss does. Or they’re like me — I need a message that works for clients as well, so mine needs to be a little more formal, even if my office isn’t.
Oh you see, I do that on purpose. That way I can use the same OOO message internally and externally. Anyone within our company can find us in the global address book. Anyone outside our company who has done business with my department has my email address & my manager’s.