I would not “share” it synchronously as @gratux recommended because in that case the data is only stored on one device and almost always accessed remotely. If the internet connection is gone, you’d no longer have access to the data and if the VPS dies, your data would be gone on all other machines too.
If you want to use Nextcloud anyways, that would be an option.
If all you want to do is have a shared synchronised state between multiple machines though, Syncthing would be a much lighter weight purpose-built alternative.