@Steve Rotherham there is no page owner automatic column related to page owner as SharePoint would have no idea who that is. You ned to add a column and add the email address of the owner. For our intranet I built a flow in Power Automate that runs once a day and checks if the page has been modified in the last 6 months. If it has no action istaken. But if it hasn't it sends an email to the page owner asking them to edit the page, change any old content and re-save. If they don't do it then it sends the emai,again the following say. This is sufficiently annoying that most do it the fisrt time they get the email.
Rob Los Gallardos Microsoft Power Automate Community Super User