So I think the cruelest thing that we routinely do to our dogs is leaving them home for eight, 10, 12 hours a day. If your life is such that your dog is going to have to be left alone for more than four hours routinely, then you should reconsider whether you have a life that a dog can comfortably fit into.
https://www.washingtonpost.com/science/2019/09/25/what-makes-dogs-so-special-successful-love/