There are several approaches depending on case by case and specific requirements. Here are some options at a very high level:
1- Create a site which can maintain archived content (you can maintain appropriate permissions as well so it can be accessed and managed by authorized users). If you want to stay with content services. Some amount of dev work needed.
- You can implement folders rules or Job schedular that will move the nodes to pre-defined archival folders in archive site baded on node metadata of your choice (e.g. modified date)
2- If you are maintaining contents that needs Security Controls and Classification, Records Management (Alfresco Governance Services) is another choice. You get all the content lifecycle start from creation to archival OOTB. Go through this doc: https://docs.alfresco.com/governance-services/latest/
3- Setup custom workflow that can be triggered by users to archive the content as a package and store it in cloud (AWS Glacier, Azure Cold etc.). Upon archival of the package you can delete the content from repo. You can implement the process to restore as well using the custom workflows as well. A lot of dev work needed for this approach.
(ACSCE, AWS SAA, Azure Admin)