From MinuteFood.

See, meat sitting in a brine will soak up some of the water; that helps make it super moist, but can also end up diluting the flavor. An alternative is to just rub the meat with plenty of salt and let it sit. Basically; the salt breaks into ions, which diffuse into the meat and make the filaments better at holding onto water. But since you aren’t adding water, they’re just holding onto the moisture that the meat naturally contains.