I think you are expecting Syncthing to be something completely different than it is.
It is only a tool to sync files of any kind between devices using a efficient protocol.
I do not even know what kind of Online Office capabilities you are expecting. You can edit files on two machines with office if you want and the process will be shared, but I do not think that is your question.
@schneemensch Thanks, it clears my doubt. Trying to find if syncthing is in tune with Nextcloud or seafile etc. and found it works on peer-to-peer method.