If we look at the previous table, it's easy to see how complex site and file permissions can get. Every organization must address permissions and architecture in the new environment, and a migration event is a good opportunity to "start fresh."
SharePoint Online allows organizations to continue using the classic site architecture components (such as site collections and subsites), but also provides a new architecture paradigm called hub site architecture to help simplify design choices and provide more flexibility. If you decide to shift to modern site architecture, you'll need to ensure that the new destination sites have the required explicit memberships.
Hub site architecture is based on modern SharePoint sites, which maintain security and access control through an Office 365 group membership connected to the site. You can learn more about developing modern sites at https://docs.microsoft.com/en-us/sharepoint...