Broken links are easy to overlook, especially on a WordPress website that has been running for several years. Pages get renamed. Products disappear. External websites remove resources. Images are replaced. Old URLs are left behind after redesigns...
Google Lighthouse can help you spot technical problems that affect the quality of a webpage, but the score at the top of the report is only part of the story. A Lighthouse audit can highlight performance bottlenecks, accessibility issues, browser...
A WordPress website can have a valid SSL certificate and still load insecure content. This happens when the page itself uses HTTPS but one or more resources are still requested over HTTP. Those resources might be images, stylesheets, JavaScript...