Good find!! I’m a nerd for learning more about suspension geometry and race car chassis setups so I love this stuff.
Found the post that explains this well. j-rho explains it better than me. See his post here:
Auto-X street - no rear sway
It’s not that a front bar gives more grip… a stiffer bar actually asks MORE of the outside loaded tires… but the tire is kept in a better range of the camber curve which outweighs the increased load, and therefore more grip!