I almost think that it is a forgon conclusion that Doc is going to the Lakers, but who knows.
I havent been as down on him as you are, but clearly he was not the fix we hoped. I think he did do some good things and at least he has the respect of the players, but he didnt solve the Embiid / Simmons mess and he has not been a great X/O coach. The problem with letting him walk is that just having the respect of the players is something, and D'Antoni has been a good regular season, pretty poor postseason coach. He might get us further in the playoffs, but he has had some very, very good teams and seems to always find a way to not succeed in the playoffs, he isnt really the answer either.
Sadly, I think it might be hard to find players that really work with Embiid. Embiid is a tough guy to combine with, he is best playing on the inside, but he wants to extend out and he isnt bad at it. He wants to get the ball at the 3pt line sometimes and create, which he can do to a great degree. I dont know what types of players you add to a guy like that, they are pretty much always going to be in his way. Maybe a coach that can convince him to reduce his offensive game to the best parts, but that is pretty tough "convince" to a guy who really can create his own shot.
I would hate to be the next coach, honestly, I think the only two possibilities are title(s) and failure. That is a very, very hard yardstick to measure up to given the number of teams out there that are just as good and players that are as physically gifted as guys like Jokic, Giannis, etc.