The problem is his asset isn’t worth what he is trying to get in return for it.

Simmons is a player with zero offensive skills, and will be a year
removed from playing. He isn’t getting a tier 1 player in return,
and possibly not even a tier 2 player if he waits until after the season.

Teams don’t need him. He needs them, because he has an asset who doesn’t
want to play for him, and that asset has low value.

He could have have gotten some great talent back before the beginning
of the season, but he told a lot of teams NO with their trade offers......

Either he moves him now and get it over with, or continue to face more
uncertainty, while Embid continues to carry a heavy load.