Yes, I believe so.
https://support.culturedcode.com/customer/portal/articles/679590
Never understand why all those 'Pro Apple minded developers' are trying to create their own cloud service while iCloud is a perfectly foundation for the most part. Don't get me wrong. iCloud is no Dropbox, not even close but where iCloud stands out above all other services is integration between macOS and iOS. Pushing and synced smaller files/data back and forward is very powerful using iCloud. It only starts to get problematic with iCloud when you use large files. For example, syncing all your Contacts, Safari bookmarks and other settings works really great via iCloud.
When you're a developer only creating apps for macOS and iOS and you're totally fine with App Store policy and 30% cuts why would you ever create your own sync service. That's the wrong mentality.