If people know you are on vacation or maternity leave, for instance, they are more likely to wait for your return to follow up. If you are at a work conference, however, they might still expect you to check your email or provide updates.
There are some types of work or office cultures where I think this makes sense. Sometimes enough people use OOO messages for work travel, conferences, and similar that getting the OOO doesn’t really mean you won’t get a response until the date specified. It can help to clarify.

I used to work with someone who had a message telling people she only checked her email twice a day. You pretty much needed to call her if you needed anything outside of those times. (She worked in a remote office.) I think she had read one of those books on efficiency that recommended scheduled email time. But there were problems with this: 4. My department often had to email attachments or text to illustrate our questions/concerns. And we were on deadlines. Reading a page of text over the phone was not an efficient use of anyone’s time 5. She did outreach & was often out of the office on site visits, trainings, or travel to these places, but never ever set her OOO for these, because she was “working.” However, she was effectively not available to read emails from other staff until after hours on those days.
First, take your pick: you can create a mellow, professional out of office email (your CEO will approve!) or, you can make an auto-reply that's a bit goofier.