It means it lives in a confined space not meant for a dog.
Dogs are for farms not cities.
Plus dog walks aren't just for the benefit of the dog.
A dog that loves your house is like the old guy in Shawshank Redemption that only has a life within the jail.
If the dog was intelligent, would it still protect you from intruders? And if it didn't, would you still keep it around?
If the dog was intelligent and it was truly part of your family, would you pay for its college tuition? Or do things you would do with an adopted member of your family like inheriting your house? Or it would be more like a slave that is only there to defend you?
So, in the end, it is all just abuse. You kidnap an animal, then restrain it, neuter it so it cannot be aggressive, discipline it to adapt to an unreasonable and unnatural standard of cleanliness and behavior, etc.
Your dog likes you because you took away its family and essentially marginalized it so that it is forced to bond only with you. And also because of artificial selection for those traits. If it was aware that it was kidnapped and forcibly sterilized it would never like you. You are just abusing a lesser form of intelligence.
A dog has to be among their own species and have a dog life. Cover large areas, sniff around, spread their scent, interact with other dogs, etc.
In a human house, living in isolation among humans that have unreasonable expectations, a dog life simply sucks.