There is this misconception that shelter dogs might need extra care, extra training, an experienced owner who can deal with all their issues. This is partly true, but it does not apply to all shelter dogs.
Behavioral issues like aggression, fearfulness etc might have to do with their past, and they might not. But not all shelter dogs have issues, and there are so many to choose from, that you would be amazed at the variety of characters and behaviors you can find in them. There are so many healthy, social, happy dogs waiting for no reason, while people go off and buy a puppy thinking that they will only know what to expect from it, if it comes along with a pedigree paper and some “breed characteristics” – as if purebred puppies come in one type, with no character of their own whatsoever.
The bottom line is that everything you are looking for in a dog, you can find it in a rescue, because there are so many of them. I am not saying that you should go off and adopt a severely sick, elderly dog with behavioral issues, especially if you are an inexperienced owner. But the healthy, social, trainable dog you are dreaming as a pet is there, also in a shelter, waiting for you to make the right choice. Are you active? There are dogs that will follow you hiking. Are you a couch potato? There are couch potatoes in shelters. Do you have kids/cats/ferrets? There are kid/cat/ferret friendly dogs in shelters. It’s simple. Numbers don’t lie (neither do I!)