CP3 getting traded is very likely, and thus sixers going all in for him is a high risk-high reward move.

The Thunder do this play because looking at all the potential CP3 offers, Bulls won't part with any of their valuable young assets for CP3, the best bucks can offer is Bledsoe and firsts that are restricted by protections and other pick swaps and New York shouldn't give up valuable future firsts for an aging point guard. Tobias is a good piece to keep them competitive with Shai and their core if they choose to be so (after letting Gallo walk), and they get two firsts out of this move too. The 2022 first will be even more valuable when you consider CP3 likely falls off completely in two seasons

The kings, assuming they want to rebuild get 4 picks, a veteran mentor for Bagley who can play next to him to alleviate his defensive struggles, a great contract in JRich whose a better perimeter defender than Barnes and Hield and a prospect in Zhaire Smith. Trading Hield and Barnes is also contract relief in the long term, as they're on deals that eclipse Al Horford's.

Sixers get CP3, Barnes and Hield which means they can have a lineup of CP3/Hield/Barnes/Simmons/Embiid, two 40% shooters and CP3 coming off a great year, and Barnes is a versatile defender and a great shooter. The biggest risk is CP3 falling off, as well as the huge salary cap hit sixers take. The counterargument to this is: sixers need to give it their best shot in a East that looks stronger than ever (especially with KD returning), and their contract situation was already looking sub-optimal with Tobias + Horford so getting back pieces that fit the rotation better with a similar cap hit can only be seen as a win for them. Reminder: They still keep Matisse, Shake and Furkan with this move so their bench doesn't get obliterated by this.