I like to have a solid backup of my Obsidian vault. File sync of any kind provides this to a degree, but not at the “restore a whole folder” level and on my first pass of using Sync I would make sure to have Obsidian open on a Windows PC at home that I knew to be backed up nightly.
For a time I used iCloud instead. It had the benefit of automatically downloading a copy to PC for backup, but it’s simply not possible to safely have Obsidian running. The constant saving of file changes was too fast for iCloud to manage and multiple versions of a file would result. iCloud was also causing memory and CPU problems on my device.