Watch a replay of the last Sixers game. Who do you think Embiid was guarding much of the game??? Okoro. How much energy do you think Embiid used on the defensive end? The Cavs 2nd possession of the game illustrated the problem. The ball is on the right side of the court and 9 of the players are on that side of the court too. The exception is Okoro, all by his lonesome in the left corner. The guy "guarding" him, Embiid, is actually underneath the hoop on the other side of the basket from Okoro! Garland tries to drive but there's nowhere to go since Embiid is waiting for him in the paint, so he actually dishes to an all alone Okoro who is heading to the hoop, where of course his dunk attempt is swallowed up by Embiid. Next possession down Mitchell hits a three, but again Embiid is 25' from Okoro, just resting on D waiting to help in the paint.
Okoro's lack of scoring is not the issue, the issue is that other teams realize that he is absolutely no threat to them, forcing Mitchell and Garland to go through an extra defender and allowing whomever is guarding him to rest. Last year in the play in JB had to yank Okoro against the Hawks as Atlanta had Trae Young on him, and Young was able to rest on D as Okoro made no effort whatsoever on the offensive end. When the playoffs come this year you will see the same thing, teams will totally ignore Okoro making it much tougher for everyone else.
Okoro doesn't do anything to directly lose a game, but he makes it much more difficult for everybody else to win one. It's why come the playoffs you will probably see LeVert playing 35 minutes a night and Okoro for about 15. Okoro is fine as a 7th or 8th guy off the bench, but in the starting line up he exacerbates spacing issues which are already difficult to play with in today's game.