stinkygobber plants with adaptations such as c4 or CAM use a lot more energy due to the extra processes (e.g. C4 plants have to convert carbon dioxide into several forms in order for it to be used due to the distance between different cells) and all these changes and transports take energy. If you take away how often rubisco binds to oxygen in C3 plants they use a lot less energy and therefore are more efficient. Therefore, when the environment is not too hot or arid, Rubisco in C3 plants will function normally without the affinity for oxygen, and photosynthesis will use less energy making it more efficent
