When Windows users suddenly discover that their files have vanished from their desktops after interacting with OneDrive, the issue often stems from how Microsoft’s cloud service integrates with the operating system. The automatic, near-invisible shift to cloud-based storage has triggered strong reactions from users who find the feature unintuitive and, in some cases, destructive to their local files.
So like syncthing but you have to pay for it and requires a server. Seems useless…
If you want to sync while not all devices are online, just spend 50$ or something and get a RPI and put syncthing on it.