There have been so many speculations on where James Harden will be traded to, but the reason why he hasn't been traded yet is simply because A, the team would have to give up too much, and B, the team would have to sacrifice everything they already have as a team to cater to Harden.
I'm just going to go ahead and say it. Any teams in the NBA that currently have a solidified "duo" would not benefit from a Harden trade, in fact, it would make the team worse. Harden demands the ball at all times, even when he is paired with another star like Chris Paul or Russell Westbrook. As a fan, you might've heard in the past that Chris Paul "is not a good teammate". Well, this is entirely inaccurate. Paul mentors his teammates and does all he can to help his team win. The truth of the matter is, James Harden is the poor teammate. Chris Paul has operated soundly on each team he's played for in the past, including the Rockets. It's James Harden that has the problem. It's James Harden who disposed of Chris Paul and Russell Westbrook. The problem wasn't Chris Paul with James Harden, the problem was James Harden with Chris Paul. James Harden wants to be the star, he wants the team to work around him, he doesn't want to work around the team.
We all know that Harden isn't the best teammate, but how could he make a team better? Harden works best with a big man, we saw it with Capela, and now we're observing it with Wood. Harden doesn't work well with another guard, which is why he wouldn't be a valid trade suitor for a team such as the Nets, Celtics, Bucks, Nuggets, Blazers, or Raptors. I left out the Heat and the Sixers because I think that these franchises have the best shot at obtaining him, and working well with him. In addition to Harden's attitude as I mentioned earlier, a team would have to give up several players or a boatload of picks. These assets are ones that the Heat and Sixers have and could trade away. If Harden went to Miami how would he fit in? Well, with no star SG (Butler has been playing the point forward/SF position) and Dragic looking to be the starting PG for this season (let's hope), Harden would mesh well with these types of players. Dragic is a pass-first type of guard, and Butler is continuously striving to get his teammates more involved. Not to mention, Harden would have a tremendously talented big man in Bam Adebayo, as I mentioned before, Harden works well with big men. However, I don't see Harden and Butler having a good relationship on and off the court. Butler is all about getting work in, and having insight on Harden's past extracurricular activities, we know Butler won't be a fan. Another reason I have Butler in the trade package deal is simply because of the Heat's cap space condition. Now let's say that Nunn ends up being the long-term starter. I don't see this operating very smoothly as Nunn is also a score-first type of guard, not looking to pass often. If Dragic is the starter, it could work, if Nunn is the starter, it would not. If Harden came to Miami, the organization would whip him into shape, and I don't think Harden will be against that. He wants to be the best player that he can be and the coaches will make sure that happens.
How would Harden fare in Philly? If Ben Simmons is traded away, things are already very clear and this is honestly looking like the best fit for Harden. If Simmons was traded in the package sent to Houston, Harden would start at PG, Curry would start at the 2 guard, Danny Green at the 3, Tobias Harris at the 4, and Embiid at the 5. If Ben Simmons happens to avoid getting traded to Houston, which could very likely occur considering the Rockets already have Wall, I don't see this being a horrible fit either. Having Harden at the 2 guard moves Green out of the starting lineup unless he gets traded to the Rockets.
All in all, Harden is not the type of player you want to trade for because he could turn your franchise upside down, both negatively and positively. A team with fewer assets such as the Knicks would obviously be the best for Harden, but New York doesn't have the talent to trade back. Harden and Paul didn't end well, Harden and Westbrook didn't end well, and Harden and Wall won't end well if they don't get Harden out of Houston.