I doubt very much that an intensively raised bird has a better life than my home-reared rare breed large fowl, and I'm certain they don't have a longer one, but it's horses for courses.
It all depends on your definition of better I suppose but try a little comparison with your birds and commercial ones.
Commercial, intensively reared broilers certainly don't live long, 5-8 weeks is the norm.
They are kept at a constant temperature, they never get cold.
They don't get wet
They aren't exposed to parasites, diseases, wild birds etc
They don't get killed by predators
They are fed a completely balanced diet at every stage of their life, they will commonly be fed six different rations to exactly match their requirements.
They have light usually 23 hours per day so the longest they are in the dark without access to food and water is 1 hour, birds reared in wintertime on natural light have to endure over 16 hours darkness without food and water.
So yes it is a short life but it is a comfortable one.
From a financial perspective it can't be done any better, as soon as a bird is exposed to lower temperatures it eats more to keep warm therefore the food costs rise, the amount of food they gain from free ranging sadly does not offset this cost.
This applies to all aspects of intensive growing, lighting, temperature etc all hugely affect the growth rate/financial cost
Unfortunately unless we want to go back to the one chicken joint per week way of life or become willing to pay a lot more for free range/organic type birds then we're stuck with this method of producing chicken.