That would be true if the mass distribution of the component is uniform. But since mass is often not uniform - such as when a large transformer is located on one side of an amplifier or a motor is located on the side of a turntable - the mass should be distributed equally among the bearings to ensure the component can move freely in all directions. Obviously cords and cables must be squared away so they don’t apply forces, including rotational forces, to the delicate set up. If mass is not distributed equally more force will be applied to one or more bearings than the other one or two. So, the best arrangement for the bearings is often a non equilateral triangle. It’s whatever gives the best "action" when you touch the component. When pushed slightly the component should return to its original equilibrium position. When the mass and forces are all balanced out, including friction, the system is in equilibrium. It’s the same for springs, the mass should be distributed equally among the springs, so the forces are balanced out, assuring uniform mass-on-spring performance as well as perfect level of the component.
