This probe is going much deeper into Jupiter’s gravity well it need a huge amount of delta V to do that hence the 6000lbs of fuel and the need for double gravity slingshots even when launched on the world’s largest payload rocket a fully expendable falcon heavy can put over 100,000lbs into low earth orbit. The falcon heavy supper stage is already the worlds highest delta V stage ever made and the highest ratio of payload to empty mags humans have ever sent to deep space it has over 11kms of delta V. The only way to improve it is to use a cryogenic third stage something spaceX has refused to do while they focus on starship. Still throwing 6000kg past Mars orbit is world leading performance. Musk did launch his car past Mars in the same rocket with star man on board just for grins.
Thanks for the info..