I moved my files on DropBox to iCloud Drive when DropBox decided to limit the number of devices you could use with a free account to 3. I kept my free account with DropBox, I just don’t use it much anymore.
I liked DropBox better than iCloud Drive, but iCloudDrive has become better and suits my needs just fine. I was willing to pay DropBox a few Euro a month for 200 GB, which is more than enough for my needs, but they won’t offer that (I asked), so now my money is going to Apple.