@janbb Yes, other animals do eat other sentient beings. But what I called the “spiritual” dimension of this issue arises because of the human capacity for compassion. I can’t fault tigers for their diet; as @hominid points out they have no real options, and besides, compassion isn’t a faculty of tigers, so the suffering of other creatures can’t be expected to enter into their calculus.
But if I lived a life as untempered by compassion as a tiger does, I’d be in prison or dead right now. Humans expect a minimum of compassion from each other. How far one extends one’s compassion is a spiritual concern. Does it just extend to only one’s family or circle of friends? Does it include just other human beings? Does it include some favored animals, but not others? That circle of concern, of compassion, is extensible and can become radically inclusive. That’s spiritual work, and it’s proper to humans. I can’t speak for other animals.
And neither can I speak for other humans. I don’t harbor strong feelings about what other people ought to eat or not eat. I have plenty of stuff I need to work on, and I’ll attend to that.