Yeah, I think 4+ legged bots should be more common than 2 leg variants. 2 legs is neat, but takes far more work and processing to control and balanced. It also requires much more powerful legs, a spider bot has more legs which makes it more "complex" in some ways, but individual legs don't need to hold and maneuver its entire body weight alone and it can hold 3 points of ground contact at all times, even when moving around, making it exceptionally stable. A bipedal robot has to be able to hold like twice its own body weight or more in order to balance and maneuver on a single foot in order to walk around and navigate obstacles.