Frankly all they really have to do is add versioning to iCloud Drive and we'd be set.Meanwhile, Apple wants to push backups to the cloud which is one of the many reasons Time Machine was stripped of the ability to recover lost emails and contacts, etc within core apps (no, Catalina’s separate volumes is not the cause, I’ve been working with Apple engineers on this issue since day 1 and it seems Apple has wanted to push time machine features to the cloud but backed off as users and developers complained). One of the other reasons Apple left the networking market and Time Capsule’s - it seems Apple wants to push backups into their cloud services as iCloud storage increases and Apple focuses on services.
I don’t understand why Apple couldn’t leave Time Machine alone and simply add the ability for cloud backups in addition to local. One or the other doesn’t make sense.
iCloud Drive is ALMOST a backup. ALMOST because while it keeps a copy of your data in the cloud, there's no versioning so if you screw up a file you can't go back to a good copy.
This is why I have iCloud Drive (and Photos too) set to download all my data to my Mac, which I back up with Time Machine.