Why is Saturn the only large planet without any trojans?
They are pulled out of stable orbits by Jupiter.
The details are in https://ui.adsabs.harvard.edu/abs/2012jsrs.conf..225B/abstract
Full text https://syrte.obspm.fr/jsr/journees2011/pdf/baudisch.pdf

The planet Jupiter is solely responsible for the hole of instability for short time integrations
($T &lt; 10^{7}$) compared to the age of the planetary system. On the long term scale this planet also destabilizes the whole region around the Saturnian libration points. If we find in the future Trojans of Saturn,
these Trojans could only be captured asteroids, in orbits in the 1:1 MMR for a short time