Trading Ben Simmons is going to be hard. I can't find too many fits and then the money and players coming back is tough. The fact that the Sixers want to get better from the trade is what makes it tough. Usually, when you trade star players it's the start of a rebuild.
Simmons for McCollum far and away makes the most sense of any trade partner out there for Simmons. The specific deal I would propose is:
Simmons and Maxey to Portland.
McCollum, Covington, and top-5 protected picks in 2024 and 2026 to Philly.
Portland moves Powell to the 2, gets a top defender in the league to fix their D, has great guard shooting around Simmons, and potentially raises their ceiling to try a new mix around Lillard.
Philly gets an excellent guard/shooter to pair with Seth Curry in the backcourt, Covington replaces some of Simmons' defense at the forward position, and they get 2 lightly protected picks to use in future deals since they are giving up the younger, higher upside star with more years left on his deal.