Cloud storage improves reliability, but it does not remove every reason for backups.
Files can still be deleted accidentally, overwritten, corrupted, encrypted by ransomware, or removed by a user with legitimate access.
Retention and recycle bins can help, but they are not the same as a complete recovery strategy.
Businesses should decide how much Microsoft 365 data needs independent backup and how long it should be retained.
Important data may include Exchange Online mailboxes, OneDrive files, SharePoint sites, Teams content, and other business records.
The right plan depends on how quickly the business needs to recover and how much data loss it can tolerate.
Cloud services provide strong infrastructure, but the organization is still responsible for understanding how its information is protected and recovered.