Hmm,

it depends what the backup is needed for. Usually backups are made for reducing the risk of malfunctioning hardware. This is not neccessary in Office 365 as the data is spread over a lot of locations. Your data is not depending on a piece of hardware anymore.

Besides of this backups are used to prevent users from accidentially deleting stuff. This can be adressed by using azure information protection to label stuff you do not want users to delete or share externally. Labeled content can't be deleted and everything else can be restored in a definable period so there is no need to backup stuff in most of the cases.

As Office 365 is a constantly changing service, a complete backup will not be achievable. There are tools that can backup documents from a SharePoint site or something like this but you will not be able to backup a whole Office 365 site with documents, planner, teams conversations and so on and restore them at a later point of time.

Considering this it depends on your specific requirements to a backup. Who needs the backup for what and what would you like to see after a restoration of your backup.

Best regards

Enrico