What is SaaS (Software as a Service) software? Microsoft 365, Microsoft SharePoint, Microsoft OneDrive, Google Drive and Google Workspace are all good examples of SaaS software but there are many more. You are probably using one and keeping your information in it.
Why back it up? Because normally a service will undertake to maintain the platform and will protect you and your data from loss if the issue is with them. But if the issue is with you then that responsibility shifts to you.
Clive Catton MSc (Cyber Security) – by-line and other articles