Some content never grows old and other content can only be used for a short period of time (or, at least, for a short period of time once a year). You certainly get the most bang for your buck if you post only evergreen content, although there certainly is justification to write time-sensitive content in certain cases.
If you have been in business for any time at all, you undoubtedly have content that you wrote and posted once for the benefit of your readers. If that content is valuable (as long as it isn’t time-sensitive), there is absolutely no reason why you shouldn’t find ways to repurpose it so that other people can benefit from what you have to say.
By now, you have so much content on your website. You don’t want to waste it. Using it once and then moving on doesn’t seem very efficient. You need to take old content and use it in innovative ways.
Content is definitely king; however, at some point, you may find that it becomes difficult to continually come up with new content on such a frequent basis. This is where recycling your old content can come in very handy.