Operating Systems are not a very well defined subject. Linux doesn't include a UI layer for instance and that isn't considered a problem. Being tied to a particular experience limits the potential applications of the OS, so in many ways I would consider the lack of opinionated experience a good thing.
There is now a UI experience available as part of Fuchsia in the workstation product, but I wouldn't overly index on it as it's just one take on what you could use Fuchsia to build.
But those write-ups were years ago and there hasn't been new reviews with much UI focus since then.