you're assuming people are good at training their dogs. it's most often the owners that need training and good luck with that. dogs that are not socialized properly early on or ones that have issues with separation anxiety, thunder, fireworks....it's a lot you're taking on. they are not pet rocks. people also need to look at their situation and then find a breed that matches it. people get fixated on a breed. don't buy a herding energetic dog and put them in a 1200 sqft apartment. they are going to be bored and destructive.
I see this so often with people my age. They want a dog or two exactly like the one they had growing up and end up in a studio with two giant dogs. My parents do the same thing and then always wonder why their dogs have issues.
Giant breed dogs like Mastiffs and Great Danes are actually very good for small spaces. They're couch potatoes by nature and need the extra rest.
this last para also explains why German shorthair pointer breed rescue groups are almost always the largest breed rescue groups in each state
It's just sad to see all these animals end up in the shelter because people got carried with getting a puppy. just because your family had a dog growing doesn't mean you are ready to have one. especially if you are doing this all on your own. I had 2 dogs growing up but we had plenty of land for them to roam. Now my sister and I share a dog lol. Well it's hers but he is here often because I watch him when she is busy with the kids/out of town. speaking of which.....he is here now for 4 days and i am exicted! a 80lb goldendoodle.