Is this concern misplaced? Not a dog show expert so maybe I'm just revealing my ignorance.
Why not just not breed unhealthy dogs, adopt the many stray dogs that persist and only once we have empty shelters consider breeding healthy breeds?
Dogs are beings, not toys or decorations.
Efforts to breed healthier dogs should not be mutually exclusive with efforts to empty shelters. I envision a world where the shelters are empty too: I don't believe it's necessary to stop the efforts to have healthier dogs until after the shelters are empty. You can make progress on two fronts at once!
When you say dogs are beings, not toys or decorations, you run the risk of sounding accusatory. I believe we have goals in common and could learn from each other without resorting to villainizing.
And as for accusing: J'accuse. People who buy puppies that can't breathe properly are insensitive jerks.
There's a classic cartoon showing two wolves in the bushes at the edge of a campfire, looking at the leftovers being thrown around by the humans. One says, "Look, what the heck, let's cozy up to these two-legged creatures that seem to have lots of food. What could go wrong?"
Next frame is a picture of an unhappy-looking pug wearing a birthday hat..
A neighbor in particular previously had two french bulldogs with no snout. They'd spend all day panting and snoring. Once they passed away they got new ones, now with snout. They spend all day running and jumping instead.
lifespan seems to be more strongly correlated by size, not squashed-nosed-ness.
Consider chihuahua, shitzu's (and crosses: bichon-shitzu, ...), poodle crosses, heck lagotto (lagotti?). All can live well past 15.
Versus GSPs, great danes, Irish wolfhounds, and so on, coming in closer to say 6-10 years.
I've never really heard argument on lifespan of pugs et al versus other dogs, though. More around (perceived) ugliness/prettiness, and their breathing issues.