Both fresh content and older content can rank good.
When someone is searching google for something that's happening right now such as information about a celebrity then google will rank a fresher article better than an older article.
But if it's just something someone is searching about and needing information such as something from history or how to fix something or do something or just general information on a subject then older content can rank good too.
I've seen articles from websites rank from 12 years ago for something I was searching for.
Google favors both fresh content and older content. But you should continue to keep your website fresh by adding new content to it at least once or twice a week to keep your website fresh in googles eyes and help boost your ranking.
I've seen websites lose their ranking for keywords when they've been worked on for 2 years or more but constantly updated websites rank better since it shows google that your website is still very active.