https://www.sciencefocus.com/space/does-jupiter-really-protect-us-from-cosmic-impacts/

Granted it's not the most sophisticated article and it seems to be behind a paywall. I learned about it in a Crash Course Astronomy episode about the Jovian Moons on Youtube.

This article here found that there would have been significantly fewer impacts on Earth without a Jupiter-mass planet, but several times more if Jupiter had the mass of Saturn. It also depends on the class of bodies (asteroids, short-period comets, long-period comets): https://spaceaustralia.com/feature/jupiters-complicated-relationship-life-earth