I think him partnering with Mac at times gave us the most stable midfield pairing (plus whoever plays the third midfielder). Still it was far from perfect. We definitely improved midfield this season compared to the last one, but despite that it feels we are really easy for teams to have a go at us. One moment we look like we have control, but whenever somebody turns the tempo up we are all over the place, unable to regain control.
With Endo it feels like he lacks physical attributes to be some kind of insurance whenever we turn the ball over. You couid live without that if you can sense the danger, but as Al says he lacks it as well. Fabinho wasn't that great in terms of speed or acceleration, but he definitely knew how to break plays high up the pitch.
I think his best game was against Man City, but he didn't really live up to that in other matches. Still really useful, but I think it's more due to us not having anyone else being able to provide as more defensive midfielder typ. And I think Endo played next to someone more defensive at Stuttgart as well.
Some interesting questions and other cases, but I think it's more for Klopp's template thread.