Gigalith

Despite Gigalith's better bulk and higher Attack stat along with a solid ability in Sturdy, it is completely outclassed by Golem due to Golem's higher Speed, secondary Ground typing giving it an immunity to Electric-type attacks, and ability to perform the same role Gigalith can, but better. Gigalith's high Defense lets it act as a decent check to Normal- and Flying-types such as Dodrio and Stoutland, but it is, again, outclassed by Golem in this regard. Furthermore, Gigalith's pure Rock typing gives it weaknesses to common attacking types such as Water, Ground, and Grass. Its horrendous Speed lets it get easily worn down by faster and stronger threats such as Simisage.