Harden is a difference maker though, even if a ring has yet eluded him. OKC couldn't make the finals again after they traded him, whilst Houston was a consistent contender the entire time they had him. Harden does have a reputation for putting up empty stats, but I think Brooklyn especially has been a tough situation for him and everyone because no-one can stay healthy there, especially this season with Harden having to do both his own job and Irving's most of the time.
Philidelphia meanwhile had to shake something up because Simmons has not developed in the same way Embiid has, and has started to become injury prone on top of that. I think it's a net benefit for them in the short term which is when they actually want to be trying to win a title; losing Seth Curry hurts a lot but you have to trade something of value back, Drummond was underutilised, and Simmons hasn't played this season.