How about I just suggest some good books for you to read about dogs. I get the impression that you don't really know that much about dogs, based on some of your remarks. I apologize if I'm mistaken.
The Genius of Dogs: How Dogs are Smarter Than You Think by Brian Hare and Vanessa Woods
How Dogs Love Us: A Neuroscientist and His Dog by Gregory Burns
Are we Smart Enough to Know How Smart Animals Are by Frans decal. ( this one is about more than just dogs )
Dog Sense:How the New Science of Dog Behavior Can Make you a Better Friend to your Pet by John Bradshaw
Our Kinship with Animals, Our Call to Defend Them by Wayne Pacelle. ( again it's about more than just dogs )
How Dogs Work by Raymond Coppinger and Mark Feinstein
The Dog by William Youth. ( I didn't read much of this one )
These are all from my kindle but there are plenty of others that I haven't read but are supposedly good reads.
Inside Of a Dog: What Dogs See, Smell and Know by Alexandra Horowitz
Our Dogs, Ourselves also by Horowitz
Being a Dog" Following the Dog into a World of Smell another book by Horowitz
What's it Like to be a Dog: And Other Adventures in Animal Neuroscience by Gregory Burns
How Dogs Think: Understanding the Canine Mind by Stanley Coren
There are many other scientific books about dogs. I don't think a large percentage of people have dogs who are miserable, but I am certainly an advocate for treating dogs and house cats for that matter humanely. It's very easy to tell if a dog is happy. All of my dogs have been very happy, as evidenced by their behavior towards me and my spouse. One just jumped on my lap for a hug. She wants some love. The other one is taking a nap with my husband. She is perfectly content.
Dogs have been bonded to humans for thousands of years. They need us and some of us certainly need them to have happier, more meaningful lives. There will always be cruel people. Some people are very cruel to their children and some are cruel to their pets. Of course, I'm against all kinds of cruelty but that doesn't mean that dogs shouldn't be entitled to the live the lives they deserve, whether they are pets or working dogs.
Since I'm an advocate for rescue dogs, I agree that it would be better if humans had not created some of the breeds that leave dogs susceptible to certain diseases and disabilities. Mixed breed rescues are becoming the most popular adoptees as more people are learning about the many dogs in need of loving homes. People need to be educated about dogs, their needs etc.
Anyone who treats a dog inhumanely should certainly be reported to the proper authorities.