Another blurb from the same site:
“Exercise is of paramount importance for these tireless, energetic animals [German Shorthair Pointers]. They are more than a match for even the most active family and they should not be taken on as family pets unless they can be guaranteed plenty of vigorous exercise. They need to be taken on a daily, brisk, long walk, jog or run alongside you when you bicycle. If under-exercised, this breed can become restless and destructive.”
This reminds me of a former neighbor’s lonely, insanely bored, extremely intelligent, high-energy Border Collie. She was acquired as a house pet, but because she kept herding the preschool boys into corners in the yard, they stopped playing outside.
She would get a glass-eyed stare and (through the fence) try to herd my moving car into a corner, me when I got out of the car, the geese on my property, birds in the air, anything that moved. Then she started ‘herding’ their toy plastic picnic table by flipping it over and pushing it around into each corner of the yard. Poor dog.
People need to do just what you’re doing before they get a dog.
Research can save people from getting the wrong dog and it’s possible the best solution to the OP’s question is to find the dog a new home.
High energy breeds of dogs require a high energy involved owner. I’m one of those and have Belgians (perfect for me). We used to be distance runners and ran with the dogs up to 20 miles a day. Obedience, tracking, dog shows and herding rounded out the other activities. If you don’t give a dog like that plenty to do they will find trouble and behavior issues.
There are low key quiet breeds. I had a friend with a basset that was a great apartment dog and good companion. Some of the big breeds are really quiet.