The Kings get the clearly superior player right now. It's all about long-term risk for the Kings and future upside for the Raptors. O.G. Anunoby fits exactly what the Kings need, and he's in the same age group as Fox, Sabonis, Monk, and Huerter. The downside is if exercises his player option and leaves after next year. The Kings already committed to this timeline when they traded Haliburton for Sabonis. The Raptors get a younger player under long-term control and a big that has played well in recent history.
I don't know if I'd make this trade, but I'd certainly think about it.