Not convinced Jaylen is a bad fit with Tatum
Furthermore, I am not convinced anyone else is a particularly good fit with Tatum either. Tatum plays better without Jaylen because Tatum gets more of the offense run through him -- accepted.
Tatum is still a very individualistic player similar to someone like Carmelo Anthony. Tatum doesn't create great chemistry with others. He doesn't get much offense from playing off of others. He is the creator. He is the scorer. And he is much more of a scorer than a passer.
I believe Tatum will have problems creating 1-2 punch with high usage PGs (like D'Aaron Fox), ball-handling wings (your turn, my turn), post orientated big men (say Embiid).
Tatum just ... does not naturally create connections with other players on the court. He is a fantastic individual player & creator. He is not a fantastic team player.
Swapping Jaylen for another star is not going to change that.