Both ${\mathrm{C}}_4$ and CAM pathways are regarded as compromises. The reason for this would be:
1. Both pathways lead to reduction of photosynthesis to enable water conservation.
2. To maintain high photosynthetic levels ${\mathrm{C}}_4$ compromises on water loss and CAM compromises on loss of carbon.
3. Both minimize photorespiration and optimize the Calvin cycle.
4. To maintain high photosynthetic levels CAM compromises on water loss and C₄ compromises on loss of carbon.