I think Yub Nub has so much more heart than VC, it feels fun and joyous. After experiencing the sombre tone of Vaders cremation, it lets us know its okay to enjoy the relief and outpouring of affection of the celebration. Where as for me VC has a tinge of sadness to it, which feels less satisfying as a close to the film and the trilogy.
I’d also say as a piece of music Yub Nub stands out and is memorable, as opposed to VC which is painfully middle of the road.