I echo GPs thoughts. I use a VPS with syncthing. While that is also clunky, it works for my usecase while keeping multiple redundant copies across devices.
Depends on what you mean by redundant though, right? Syncthing is generally not gonna protect you from an accidental `rm -r *`, unless perhaps you set yourself up with a permanent head server where everything is versioned but on which files are never edited. (I'll be happy to be wrong)