Kobo is headquartered in Canada. Their ecosystem was developed based on Canadian law. Under Canadian privacy laws, if Kobo starts storing ebooks for their customers, they must allow the customers access to the information on their books stored by Kobo. You did notice that on some devices, Kobo allows the customer to store books in the customer's cloud (either DropBox or GoogleDrive)?
This discussion has been going on for over a decade. See
this message from 2013. The Personal Information Protection and Electronic Documents Act is still the guiding document in Canada.