Using the SharePoint Site Attestation Policy

The site attestation policy is designed to require site owners to make a positive statement that the settings of their site, including its current membership, are accurate. The idea is that requiring site owners to attest that their site is still needed will force people to decide whether sites are still in active use and should be kept online. If not, the policy can move the sites into Microsoft 365 Archive.

https://office365itpros.com/2025/10/30/site-attestation-policy/