Onedrive at least works great in my experiences. I bave a dropbox account, but my uni supplied me with a huge onedrive allotment. I sync every user file on my computer and I can access it anywhere with an internet connection. The msoffice integrations are great too, and ms office online is pretty feature rich.
Dropbox had a great idea, but it's not hard for a large company to copy it like microsoft did. Apple just does a lot of things half assed if it's not a priority to them. Nothing stopping iCloud from being better than dropbox in a couple years if apple one day decided they gave a damn about it.
OneDrive and OneDrive for Business (which is really the Sharepoint thing) really has turned out to be good. We’ve been using it for about 3 years now in our small business which is mostly a Mac + Office365 + Azure AD shop.
We have a mix of iOS and Android, and some physical and virtual Windows 10 PCs.
The macOS sync client is generally very fast and keeps out of the way. It gets tripped up occasionally, but no more so than any other. It was really clunky when we first started using it for Sharepoint, but they seem to be iterating fast these days and we see very few issues at all.
For Sharepoint365 the sync client means our people just treat it as our “cloud network drive” with selective folder sync options (we don’t use any of the other Sharepoint stuff).
If you’re an Office365 shop, the integration is incredibly nice. I can start work on a Word doc on a PC and save it in OneDrive or Sharepoint365, and then on my iPad open Word and the document is sitting right there as the last file I worked on in the File>Open screen, with a “Go to where you left off” marker when the file is open.
We tried Box and liked it initially, but it became hard to justify it in the face of easy functionality and pricing from Office365+OneDrive. iCloud isn’t flexible enough for most of our business use cases. DropBox performance was always an issue and we didn’t want to saddle our dev laptops with that performance hit.
What's more, you can likely (depends on country etc) use Office desktop apps and your OneDrive storage on any supported device, including native apps on Android-supporting Chromebooks, for free as long as you have your student ID, as part of their Office 365 for Education programme -- see my other comment (works for teachers too).
They're really competing hard in this space, and I suspect they're trying to get ahead of Google One here. They've already left Dropbox far behind.
Dropbox had a great idea, but it's not hard for a large company to copy it like microsoft did. Apple just does a lot of things half assed if it's not a priority to them. Nothing stopping iCloud from being better than dropbox in a couple years if apple one day decided they gave a damn about it.