It turns out this was the original reason for Steppenwolf and his Parademon army invading Earth thousands of years ago in Justice League, as revealed by Weta Digital, which handled the visual effects for that sequence. among other things.
Darkseid is already one of the most powerful beings in existent, but he’s obsessed with piecing together the Anti-Life Equation so that he can erase all free will.
In the comics, he’s frequently targeted Earth because he believes part of the equation reside in humanity’s subconscious.
For those unfamiliar with Jack Kirby’s Fourth World mythology, the Anti-Life Equation is a mathematical formula that, should someone solve it, would allow them to gain total control over all sentient beings in the universe.