Why Backup
Microsoft does not backup your email, contacts, calendar entries or your sharepoint sites.
Ransomware can destroy a business and hold you to ransom. You cannot recover without a backup.
Dropbox is a syncing tool and not a backup solution. Ransomware can destroy your data.
OneDrive is a syncing tool and Microsoft does not backup your important data.
A Virus will attack in the background without your knowledge.
Computer / Server hardware can fail. This results in your losing data without a backup.
Hacker take their time accessing your business without you knowing and delete all your data.
Flood, fires and break ins could destroy your data. Could your business survive.
Human errors means data can be deleted or disgruntled employees can leave on a grudge.