What is the rush to maturity with dogs?

Recently I acquired two meat chickens. If you are unaware, there are different types of poultry.

Depending on if you raise them for meat, for eggs or dual purpose. Dual purpose means you can use them for both meat and/or eggs.

These are the first meat birds I have personally owned, they were purchased by accident from someone who was looking to have only a couple egg layers. Being that I have a large coop and area for chickens, they offered the birds to me. I took them, mainly because I have not experienced this type of birds and was curious to the differences. For anyone that doesn't know, most of the chicken meat purchased at the grocery store is from chickens that were slaughtered between 6-8 weeks of life. They have selectively bred chickens to grow/develop younger so that one can yield meat as quick as possible. I spent some time researching the breed (Which is a Cornish cross) to find out more about the breed in general, lifespan and health issues. I was shocked to fin out the similarities between these chickens and most mastiff breeds. Some of the issues I came across were that they are prone to hip dysplasia, sudden death, heart problems and a shortened life span in general. As I read this I could feel my heart drop, these extra large chickens that were lumbering about my yard were still only 7 weeks of age. SEVEN WEEKS, still making chick noises and their feathers were not fully in. Yet, this is the best time to slaughter this specific animal? We created this animal, to grow meat as quickly as possible, without thinking of the animal within. That this is a living breathing creature, that if it even has the chance to live past slaughter date, it may drop dead anyways due being built like a cartoon character. I decided at this point I would allow both to live until their body said otherwise, I was curious and truly hoped to see them past their first birthday. Sadly, the male passed by 11 weeks. Yes, I found him before he was useless to harvest the meat... Yes, we ate him. He could no longer hold his body up and seemed to be suffering from heat stroke, so we ended his life. The female has lived throughout this summer, she lumbers and can not run. But is one of the sweetest birds I have owned to date and enjoys being around humans, I believe they also bred them to not be flighty to make harvesting easier.

Bringing this conversation back to dogs, I found a lot of correlation between these birds we bred to harvest and our very own dogs very similar. Do we unconsciously want animals to develop as quickly as possible? When we take almost two decades to do so ourselves, why do we expect dogs to grow and mature what we do in twenty years in two? By doing this, I believe we have shortened these animals lives because we are asking them to age in a unnatural amount of time. What are your thoughts?