Seba's poor form is mostly from him missing sitters and trying too hard. Jozy does clear space. It's not that Seba is 'the guy' to benefit. It's that those few seconds where Jozy draws defenders gives slow motion thinkers like Osorio and Delgado the extra seconds they need to find the right pass. When Jozy is in, these things happen as there is more time for our supposed midfield play makers to try to make plays. Without him, these players wait so long that all shots and passing lanes are gone so they play square or backwards passes and our attack stalls.
I said before Osorio has zero hope of being a useful AM (or really just a starting mid) on our team. Now I will say that when he did look decent, it was when Jozy was in and he had more time on the ball to process what was going on. Forget the Seba stats, a healthy Jozy makes the team better and that's what matters.