Your website has limited power for the total of everything it does. So any files, emails, databases, cron jobs, addons, redirects, sub domains, and logs, on the website that is not needed will take away from the power to use on the files that need it more.
We highly suggest time to time going through your website and removing any of this things to make the website run as fast as possible. This will give you better SEO, better repeat visitors, and a happier user experience. It also makes better back ups that can be restored faster if needed.
Optimizing your website is always a good idea.
