This is false. Apple OS's contain numerous blockers and friction points that not only stop users from storing much of their data in other clouds, but prevent competitors from being able to develop them at all. Apple does this via elevated privileges/processes and proprietary API's available ONLY to Apple's own local apps and cloud servers, for example:

- If you backup your photos to iCloud, everything happens in the background with elevated priviliges and "just works".

- If you backup your photos to ANY other provider, they run in a separate sandboxed process which doesn't "just work" because the OS can kill it at any time, meaning users often need to leave 3rd party apps open for their photos to sync at all.

This is the same for every 2nd/3rd party service in comparison to Apple/iCloud across Apple OS's. Nobody can develop a true competitor for anyone who purchased Apple hardware as Apple has access to a range of processes, services, and API's which are not available to external developers. You can't boot up an iphone and set Backblaze B2 or Amazon S3 as your authoritative cloud data or backup provider. You must use iCloud, or you get an inferior experience – not because of any technical limitation, but specifically because Apple designed non-Apple integrations to be inferior.