I am currently using Microsoft 365 with sufficient storage. Do I still need a separate data archive? 

While Microsoft 365 may offer sufficient storage in active mailboxes and OneDrive, this alone may not fully protect your critical data from accidental or intentional deletion, theft, or corruption. 

Microsoft 365 includes features like Exchange Online archiving, legal hold, and retention of deleted items, which can extend inbox size and offer some level of protection. However, these features may not provide a complete, up-to-date copy of all your data or offer the advanced search, discovery, and compliance capabilities that a separate data archiving solution can.

For organizations with specific regulatory or legal data retention requirements, or those needing more granular control and comprehensive eDiscovery for historical data, a dedicated data archiving solution for Microsoft 365 can significantly enhance protection and compliance.