OP, let me share a couple of stories, of situations I’ve known people like that with dogs.
I used to look after a dog who had continuous human company, his owner was an alcoholic in his very early days of recovery when he got him, owner was quite ill and unable to work at the time. He was alone except for the dog. No friends, no family, the dog became his everything. A real companion. As life got back on track for him, he gained more confidence in his sobriety, and he went back to work, he couldn’t face the prospect of his dog being on his own, so he went to work with him, they’d share KFC in his car, if his dog wasn’t invited he wouldn’t go- anywhere. Understanding that the first thing he had ever been solely responsible for was his dog, and the love he gave him was really heartwarming.
His bosses eventually banned the dog from work for safety reasons.
I started to look after the dog, to be fair he was the loveliest company. He just loved his humans- for a year i was never without him because he was no trouble, really lovely boy to be around who thought he was human.
On the flip side. My current dog, he goes everywhere with us because he ruins the house when we leave him, he’s calmer and I don’t have £££ of damage and cleaning to sort when I get home that way, and I know if he continues to ruin my home that I’ll have no choice but to get rid of him, and in fairness I can’t do that to him.
With all due respect, if you don’t come to the conclusion on your own as to why he has his dog with him all the time then long term this won’t work for you.