Page group access

In documentation group access is managed with frontmatter:

     login: true
     groupName1: true
     groupName2: false

Why it is not a attribute
groups: [groupeName1, groupeName2]

How to industrialize group access with page acl ? I mean there is no inheritance of access by default, or it is not possible to set defaut access to a page, or modify it dynamically through the form advanced tab in admin ui.