Mm, you'd think, but this is not always the case (in fact, not often!)...
I know a LOT of people, living in a rural area, who breed gundogs and herding dogs, not a hip or elbow, heart or eye test among them.
They breed every year, they're always running on dogs and training new dogs because they will sell part trained or fully trained dogs as well as puppies, and want to keep one or two for themselves.
SO if it turns out that one is badly affected by an eye problem or a hip problem etc (and often these things are not noticable for years.)
I have seen dogs who have lived with severe hip dysplasia, literally no hip sockets AT ALL and huge arthritic changes, whose owners had no clue at all, its shown up on an xray for something else, and because the dog was fit and lean for work, they just didn't notice, but the dog would have been in severe pain that whole time. These dogs are typically the ones owners will say 'oh he's great at work but don't let the kids near him' or 'he's a fantastic dog on the sheep but he can't be trusted in the house/pub/car...' etc Clear signs that the dogs are not happy but its something that can be ignored in the lifestyle they lead...
If it can't be ignored or affects the dogs work, the dog is put down, move to the next dog.
Pet dog owners are generally not happy to live with dogs who are in pain, exhibit behaviour problems as a result of that pain, or to just put the dog down and get a new one.
So yeah, IF you can find a working dog breeder, and you want to work your dog, and they are doing proper health testing and have been for generations of these dogs (because just health testing the parents but no results for grandparents, great grandparents etc, is not particularly useful!)... thats a good choice.
If you don't intend to work your dog, if your lifestyle and home life doesn't really match up to that of the breeders.... might not be the smart choice at all.