If C4 photosynthesis prevents photorespiration, why haven't all plants evolved to use the C4 pathway?

Question

Quizplus · Accepted Answer

The C4 pathway is not advantageous in all climates, as it requires a higher temperature and higher light intensity than the traditional C3 photosynthesis used by most plants. It is most advantageous in hot, arid environments where water availability is limited. Additionally, the process of evolving a new metabolic pathway involves multiple genetic changes and can take a long time, so it is not necessarily the case that all plants will eventually evolve to use C4 photosynthesis.

If C4 Photosynthesis Prevents Photorespiration, Why Haven't All Plants Evolved