The integration into the Apple platform is the main reason to use iCloud and where it really plays out its advantages over alternatives. I only have faint memories of the support on Windows which is much more restricted. iCloud is not just a storage space but a central for a lot of services used on Apple devices. The file system integration on macOS and iOS is a completely different thing than traditional synchronization folders.

While their default free 5 GB is like nothing, their add-on prices are acceptable. A buck monthly for 50 GB storage space.

Too bad that it's not E2E encrypted, so Apple can see all content. Also Apple works with authorities, so if we count 1+1 together....

Too pricey compared to competitors. No E2E encryption.

Although I like iCloud because it allows me to see files across Apple devices, it's not very friendly directly on the Mac, and totally ignores Windows and Linux devices. Accessing iCloud via a browser is a joke. You can only download one file at a time. Not directories. On the MacBook Pro, Apple has gone the way of Microsoft - burying your files under obscure directories under ~/Library/MobileStorage/com~apple~CloudDocs. I've always been used to keeping my Documents, Pictures, Videos, Desktop, etc. right in my home directory. This is not acceptable to me because I can't always remember that long directory path to get to my files on my own computer. And if I move the directories, bye-bye iCloud sync.