Add SharePoint admin as the site owner automatically, when a site is created in SharePoint online

You can easily from the new SharePoint Admin center add yourself to any classic site as an admin, or as group owner all from the SharePoint Admin center on all sites. Adding someone to every site is going to cause a bad experience using delve, search and personalized news for that poor admin :P.

But if using the new SharePoint admin center to easily add and remove yourself from sites your only option is to use a power-shell script to add yourself to all sites on a scheduled basis but doing this will cause that person to have all files showing up in relevant searches, recent activity, news, of all sites rolled up for that individual.