The ancients were significantly less nice. Crucifixion is a slow and nasty way to go. And of course there’s scaphism whixh is so appallingly nasty that revisionists deny it was ever practiced.
Perhaps I am just a pessimist, but I think it's far from a guarantee that we will only progress. I have no reason to believe that people today are any more civilized than 500 or 1000 years ago. Our much improved technology sure does look pretty though.
Indeed, just look at the ongoing wars today - exactly the same level of brutalism and violence like hundreds years ago, if not more due to the improvements in weapons technology.