I’m late here..
(all imho…)
Not good: Having data exclusively on a cloud instead of on a local machine / local drive
Not good: After macOS updates and after new install, macOS sets some user folders to iCloud
Good: iCloud as a storing device, controlled by the user (as far as possible)
Good: Having iCloud-Sync for personal SwiftData applications. Phantastic - but not yet matured
My data is on a local RAID system connected to my main workstation (macOS, MacMini). Using ChronoSync, all data is synchronized to 2 local NAS (backup, too slow for working on bigger files (Photoshop, FileMaker, etc.)). Yes, there are backups on external drives in a save on a Bank here in town.
(I can not access my local network from outside - but I can access the data from inside the local network).
If I need some files on several machines out in the wild (MacBook, iPad, iPhone,) I copy those files to a folder on iCloud, removing them after work
We do have a stable ‘internet-connection’ (fibre) - but there are possibly times where the connection fails or is slow (just think about that AWS hiccup this week..)
I am really happy with that configuration - and I never would have my data exclusively on a external, foreign storage
We got some wonderful customers, running wonderful small shops in really nice down-town places. Two of them had set the storage to iCloud, just because it is/was a default setting (they didn’t even realize). Both had big problems running their business (local FileMaker databases). One had a disk-full (iCloud) message during Christmas sales and the employees didn’t know how to deal with that. Terrible situation!
iCloud is often used here and over the years, there weren’t problems (knock on wood). And Yes: Apple was better some years ago…