I wanted to chime in and this looked like a good spot.
My dog is a mix. I did not buy him that way. In fact, I was fairly ignorant of dog stuff, in general, aside from having been around dogs in my life, all of them purebreds. My grandparents had a champion Apricot Poodle named Danny. He was a little too tall to show but it turned out that he could sire show-winning pups. And he was retired from breeding at about 3 or 4 years old. My granparents, not being breeders, gave him a home and then learned their lesson a little bit later when he sired a litter with their Black Poodle, Cassie (named after Mama Cass in the Mamas and the Papas.) Being unable or unknowledgable about keeping intact pets, they had him neutered after that.
Shadow was bought by friends from a pet store. The breeder, listed on the purchase papers, does not show up on any lists. No breeder lists, no puppy mill lists. More than likely, a byb or an oops litter, like my granparents. I like to describe him as a bubba with a box o' pups. A clueless redneck. Though, he might have done it on purpose, though still haphazard, such as not providing contact information to track how well the mix is doing. That is, it might have been fine, theoretically, to mix two breeds to see if the resulting dog is an improvement over either but you need numbers to quantify that.
Some geneticists will tell you that mixes are generally healthier because problems that are doubled by close sanguinity line breeding are stopped in the resulting litter, mainly because the recessive in one parent did not find a complement in the donation from the other parent. Problem is, when you want to continue that mix, you start to run into the same problem as pure breed breeders. What recessives in each parent are going to double up? Also, most byb's and mixed breeders are not savvy to what happens in the formation of a zygote. The nDNA recombines or shuffles the deck in the conception of each zygote in a litter. That is why one litter can produce varied effects from just the two parents. It's havoc on a breeding program but, by evolution, it is the way of the world. Mutations are created and the ones that best allow the zygote to survive in the world get passed on. My co-worker, John has a Sharpei named Augustus Caesar (Gus) and both of his parents are black but Gus is fawn. Also, because of the way that nDNA recombines, you can't accurately predict results with just the mendelian math model. That model is only good for a statistical forecast. The proof is in the pudding, as it were.
Shadow seems to be a good dog and the only defect I can see is that sometimes, when excited, his scalp gets a cramp pulling down on the right side. A little massage helps. I think it's a result of the genetic shuffle. Sibe ears are held up and Lab ears hang down and his neurons get confused. So, let's say he is a good dog and fairly healthy. At 5.5 years, he has yet to show any signs of Hip Dysplasia. His vision is good. He is over standard height for either breed. Kind of underweight for a Lab because his bone density is that of a Sibe. So, let's say that the breeding of his parents produced a fairly good dog. Well, even a blind hog finds an acorn, once in a while, to use an old expression. And it's no guarantee that litters from him would produce other healthy dogs.
As for jobs, most breeds had jobs and there is no need to mix breeds to create superior working dogs. There is no need to mix breeds to improve one breed. But people have created new breeds from mixes. The Dogo de Argentino is one example I can think of. But even so, once the new foundation was established, rigorous breeding practices were required to refine the breed to a standard of form, workability, and temperment to meet the job demanded of them.
Even the Alaskan Husky, which is not a breed but a type of dog, starts to fall under rules of breeding. A "legitimate" AH breeder only breeds from dogs from winning teams. And their desire is to create the biggest, strongest, fastest sled dog, which has nothing to do with temperment in a family. AH breeders would like you to think that the ones that do not make the team live out their lives still being worked by mushers but that is not the case. That would be too many dogs to hang onto. Out of 3 litters in a year, 6 might make it to a team. That leaves an average of 9 dogs who were not bred for temperment or obedience to wind up somewhere else or culled.
And so, I think, the ideal of creating an "hypoallergenic" dog, which sounds like an oxymoron to me, is doomed to failure. First, how do you determine the hypoallergenic status on shedding, alone? Sorry but the allergic reaction is not to the fur, it is to the dander. And every dog produces dander. So do humans. It's how we get rid of dead cell tissue. I saw a Labradoodle at the Dallas SPCA. And I could smell him from 15 feet away. Sorry, but those dogs need grooming. And wouldn't be easier to have a Poodle, whom you can groom regularly be shearing the fur? Besides, Labs are constant shedders. They don't specifically blow coat because they shed all year round.
As for titles. The next door neighbor hound mix has a CGC. And she would regularly get over the 6 foot fence until they added to it, increasing the height to 7 to 8 feet tall. She likes to bark at Shadow and sometimes lords it over the mini-Schnauzer who is her yard mate. CGC doesn't mean she should be bred.
Mixed breeding is the same as rolling dice. You might hit 7's. The chances of that are roughly 1 in 43,000. It is more likely that you will not hit 7's. The house always wins. That's a rough analogy and there are more factors than just gravity when it comes to genetics. So let's discount half to account for fatal recombinations where the zygote never takes off. About 1 in 21,000. Just for giggles, let's assume a 50 percent chance of viability to be egalitarian to all breeders. 1 in 10,000. Let's cut that in half to assume a 50 percent chance that no big health problems will diminish the life of the dog, at least not right away. That's 1 in 5,000. The odds are still against producing healthy, superior dogs from just willy nilly breeding. Unless you start tracking genetics and generations, like a pure breeder. In which case, why not just purebreed?
Yes, there are purebreeds with problems. But the solution is careful breeding, not rolling the dice.
I know next to nothing about breeding and most who are going to buy mixed breeds on purpose probably know less than I do. That's not an insult, just a forecasted judgement. If they knew something about genetics, they would second-guess their own decision to buy a mixed breed. It's probably a good bet that 50 percent of those will wind up in a shelter. Not so hypoallergenic at all, too much work, baby on the way, moving, "untrainable," etc.
As others have pointed out, there is so much to breeding besides just putting a couple of dogs together. And I'm not aware of such standards in mixed breeding. Almost by definition of the term mixed breeding, it would seem antithetical to careful breeding.