Withholding food and water was the specific protocol for your father, based on his condition. Presumably, at the time hospice began medicating and withholding nutrition, your father had not been sitting up, interacting with people, feeding himself, and not in one of the stages near death. I’m sorry for your loss, by the way.
Every case is different. My mom had food and water withheld because she was heavily medicated and rapidly dying (rapidly dying even without medication). Once someone has reached a certain stage near death, food and water are taken away because there is a risk of aspiration, which can be horrific and traumatic in ways a peaceful death for a loved one are not within hospice. And that is the goal of hospice: a peaceful death for the terminally ill and comfort for loved ones and the dying.
My uncle is currently in the care of a hospice team. He has been for several months. He eats, drinks, etc. When he reaches that point where he’s rapidly dying, food and water will be withheld and medications will be administered to keep him comfortable and peaceful.
My point is, hospice doesn’t starve and dehydrate people to death. By the time food and water are withheld, the person is already at an end stage of life and neither needs, nor should have either.
My father ate right up until he couldn’t swallow anymore, not even frozen ice (he would cough and the danger was aspiration at that point) and that was about 3 days before he died. Every patient is different as well as their sufferings :( Luckily, he really had no pain. Some cancer patients have terrible pain, fluid retention, etc. We were encouraged to start giving small doses of morphine during the actual 3 day dying process to help with breathing issues as it does open the airways. He never went into a coma and we could tell he heard us right up until he died (he’d flicker his eyelids or flap a hand if you called his name).