A WordPress site that is not maintained is a liability. Security vulnerabilities, broken functionality, and performance degradation accumulate quickly. Here is what monthly maintenance should actually include.
Updates, But Not Blindly
Update WordPress core and plugins monthly, but stage it first. Plugin updates break things. If you update 12 plugins in production without testing and one of them causes a white screen, you have a problem. Use a staging environment, run the updates there, test the critical pages, then apply to production.
Backups, Off-Site
A backup that lives on the same server as your site is not a backup. Use a service that stores copies off-site, UpdraftPlus to S3, or your host's off-site backup. Test the restore process at least once a quarter. A backup you have never restored might not work when you need it.
Security Scan
Run Wordfence or Sucuri monthly. Look for malicious files, unexpected admin users, and file permission issues. A hacked WordPress site can be cleaned, but it takes hours. Monthly scanning means you catch problems early.
Performance Check
Run a PageSpeed Insights test monthly. Note the score. If it drops significantly from the previous month, a plugin update or content change is likely the cause. Catch this early and it takes 20 minutes to fix. Catch it 6 months later and it is a bigger problem.