We put dogs down every day because they have incurable diseases or are suffering.
I had to put my dog down a few years ago because she was so old she could no longer get up or control her bladder or bowels, and I felt guilty for letting it get that far. I still remember the look in her eyes when they gave her the pain killers to knock her out, she looked so relieved.
I don’t understand how I get to make that decision for a dog, but a grown human, in most places, can’t make that call for themselves and go out in a peaceful and controlled manner. If I knew I was going to die painfully in a few months or a year, I’d definitely take an overdose or nitrogen asphyxiation over the disease. When dogs have a better way out than people, something is seriously wrong.