Similar to how I feel about the poor highly brachycephalic pug you have as an avatar - they shouldn't exist in the first place. However, I do understand that they appeal to some people, and maybe I can do my part to change the public perception of them to make them obsolete (the senseless attractions and brachycephalic pugs, not their fans).
We started breeding pugs to create a medically sounder breed. Every dog breed has its own issues, and the pushed-in face of a pug makes it a bracheocephalic breed, and it's also known for luxating patellas and serious corneal ulcers from its very globular eyes. What actually outraged us enough to start breeding were two dogs with eyelid entropion, lashes growing on the inside of the lid and abrading the cornea. But being a bracheocephalic breed does not automatically make pugs poor breathers, rather loud breathers or snorers, and in 9 generations of dogs, I have had exactly one URI. We set out, through highly selective breeding, to breed specimens with no patella luxation, a much less globular eye (one much less prone to scratching and dry eye), and none of the three traits associated with bracheocephalism.
This is certainly an odd place to be schooling you, but since you brought it up, there is no such thing as "highly bracheocephalic.". That's like being "highly pregnant" or "highly dead." A bracheocephalic dog does not have a snout, and three distinct potential, and distinct, problems CAN, but don't automatically, occur from this. One is stenotic nares, very narrow nostrils, through which it would be difficult to pass air. The second is an elongated soft palate, which extends into the trachea and potentially reduces air flow. Just as stenotic nares are plainly visible at an initial vet exam, an elongated soft palate is not only visible to a vet, but reveals itself by a clicking sound of the tissue flapping on inhalataion and exhalation. If a puppy has either of these conditions, a vet will deem it unfit for sale so that an unknowing buyer won't have heartbreak or major surgical bills someday. The third feature, a collapsing trachea, which if it were to occur, is a fatal event, and can occur at any time in any dog's life.
It requires selective breeding to, not unlike SSP decisions, determine which specimens to breed. Quite simply, you eliminate from consideration breeding any dog with any of these potentially-unhealthy traits; until this combination of "good" genes is reinforced in enough generations, recessive genes can emerge with an exception or two, but by the fifth generation, our vet, who had obviously examined all our puppies, said we had the best eyes, nares, palates, and knees he had ever seen in a pug. That makes for a dog that is happy and healthy for the longest time possible, making for equally happy parents. And of all the pugs we sent out into our extended family of pugs over the years (a family close enough to us to send many dozens of Xmas cards and routine updates every year), not a single owner ever reported a collapsing trachea.
While many dogs have physical jobs they are ingrained to do, like hunting, herding, fishing, or birding, pugs also have a job they were bred for--companionship. At one time, these there the dogs used to cheer up children in hospital wards, because they innately discern your moods and thoughts and minister to that or celebrate that. One line of our dogs included a little girl who could not only tell your mood, but howled if you had a headache or some physical ailment, as if feeling your pain. We called her the "Sensitive Soul," and new widows or those who had just lost their beloved dog would wait to reserve a puppy who would provide just this degree of empathy. They are, of course, also clowns born to entertain you and bring you joy. We even developed a line of athletic pugs, the forebear of which could jump a three-foot fence from a standing position and whose feet hardly seemed to touch the ground when running. There are reasons for pugs to be in this world, and in nine generations, we proved that this did not have to come at the cost of physical health.
For someone impertinent enough and insensitive enough to pick on someone's avatar that in no way relates to the thread at hand, I assume it's necessary to point out that we never made a dime on this venture. Doing what's best for animals always comes at a cost, and with many, many C-sections in addition to all the regular health and husbandry, we lost thousands of dollars each year despite selling puppies.
For the rest of you, two little tales that show why pugs belong on this is earth. First, the dog in my avatar that sent Batto into a rant is my 8th generation boy Otto, now 10, who has just passed me in age. At his recent dental cleaning, a passing vet remarked on his eyes, having no corneal scarring or dry eye, and his utterly silent breathing. Otto knows how hard a C4-C5 disk problem has made both writing and typing for me. As an English teacher, that's a lot of agony, because there are lots of essays and exams requiring my feedback. So whenever I do schoolwork, he's right there, very often sitting ON the schoolwork itself as if to take on my burden. If you look closely in my avatar, you'll see him sleeping on "blue books," little booklets of lined paper produced for exams. That's why this picture is my avatar. Breeding for medical soundness has enabled me to enjoy Otto, who is also "practically perfect in every way" from a conformity standard, empathizing with me and sharing some of the weight and the pride of my world.
Remember that third trait of bracheocephalic breeds, the collapsing trachea? Never a report of any--until it happened to me. Otto's father, Max, chose me as his human from the moment his eyes opened in the whelping box, and no one has ever loved me more. My ex-husband used to say he practically batted his eyelashes at me. At 11, he developed a lesion on his spine that resulted in hind-end pareses. He could not feel the sensation to urinate, so he had an in-dwelling systostomy tube placed into his abdomen with a bag to collect urine. I decided he should live in my bed. Otherwise, he'd be getting the bag stuck around chair legs and pulling out the tube and all sorts of other mischief. Since he could only pull himself around by his front legs, he didn't miss wandering. He lived in my bed, but I took him with me everywhere I went in the car, so we were still together, best buds. Then, in 2016, I had to have both of my knees replaced. I was only in the hospital 3 days, and my daughter was taking attentive care of him in my absence. But it didn't matter. He was beside himself, panicked that something had happened to me, and he barked and barked and barked in alarm, and nobody could calm him. He barked solid for about 60 hours, and the minute I got home, I could tell that his trachea had collapsed. We euthanized him the next day. It was a collapsed trachea caused by trauma, not genetics. My Max died at 13.5 of a collapsed trachea because he loved me so much. That love is why the pug as a breed is loved so much.