Is evolution lazy?

I've always thought the motto of evolution and natural selection to be: 'If it ain't broke, don't fix it'. Take plants for example, their chlorophyll has a green pigment meaning it reflects all green light, and it can't be used in photosynthesis (plants only absorb 3% of light that hits their leaves). Why isn't the chlorophyll red, or yellow, or colour that excludes less light though? Well the explanation for that is simpler than you might expect; because during the trial and error phase of the chlorophyll development in evolution, green was probably tested, it worked well enough for plants up to a certain size to meet their sunlight absorption needs, so it was kept. The plants weren't exactly capable of testing the best pigment colours in a longitudinal study; once they found one that worked, they kept it, and 'if it ain't broke, don't fix it'. This may be the reason that plants don't have a central nervous system like animals do. For animals the CNS is vital, as we need brains capable of problem solving, fast impulse conduction from sensory organs via neurones, co-ordinated movements, and the ability to feel pain, in order to survive as omnivores, in finding food, remembering the best places to find said food, evading predation, reproducing and to find suitable habitats. Whereas plants can survive perfectly well using photosynthesis to produce sugars, relying on insects and the wind for pollination, and using plant growth chemicals like auxins to respond to environmental stimuli in like sunlight (phototropism) by promoting cell division or elongation, because plants don't have an endocrine system like animals do. But it's because they don't need one to survive, that they don't have one. Plants have never needed to evolve a CNS by natural selection to survive, as they can produce all they need as stationary entities, without the need for complex thought or electrical impulses, ergo they don't have a spinal cord or brain. Because 'if it ain't broke, don't fix it'...