I grew up in rural Australia, an unpopular opinion of mine, is that large dogs should never live in apartments, I think it is cruel. (whether they are "couch" potatoes or not)
My unpopular opinion is that people should never live in apartments because they are cruel.
Listen to your dog.
Find yourself a plot of trees and fields. Walk through them every day. Stand out in snow and rain. Listen to the noise the weather makes. Plant something you can eat every year. Pee on a tree. Make friends with a crow.
Life is too short to spend it surrounded by asphalt, cement, and tall buildings.
I feel that people in dense living situations have cut themselves off from what I call the "emotional wild." Living with a dog's sense of the world is healing in many ways.
The next time you have a strong, but not dangerous, precipitation event, go somewhere you can't hear cars, wear protective gear (rain/cold) and stand out in the weather. As the scandies say, there is no bad weather, only bad clothing.
Listen.
Find your sound. I like the hiss of hard snow falling through pine trees.
Smell.
Take in the smells of the world around you as if you were smelling the nuances of a fine-cooked meal. Let your nose be your eyes and see how a dog sees.
Feel
Notice what the weather feels like when you are surrounded by it.
When you get back home, don't stop noticing sounds and smells. It will give you a better direction than staying in your head.
I had a Bernese Mountain Dog, about 120 lbs (55 kg) of floof. We never lived in a property with a yard or garden, it was always either a townhouse or apartment.
I understand what makes you think that big dogs in an apartment can be cruel, but I think that it's identifying the wrong problem.
Dogs need the right type of exercise and stimulation. Some of this is breed specific, the Aussie/Great Pyr mix up thread would probably have needs closer to my parent's Border Collie who needed (and got) double digit miles per day of movement. A Bernese Mountain Dog has lower energy needs.
As apartment dwellers we made sure that he walked many times a day, often in wilderness areas (an advantage of the PNW), but also often in dog parks, beaches, etc.
I've seen people who have gardens/yards assume that allowing their dog access to the yard is sufficient, rarely if ever walking them.
The key, as with almost all dog or pet issues, is the owner attitude, and has little to do with apartment vs house
