Religion

I mean, Moses wasn't that far removed from people literally living in caves, or at least hunting/gathering. Agriculture didn't begin until about 12,000 years ago, and didn't really change how societies operated until a bit closer to Moses' time. In Moses' day, slavery and brutality were widespread, considered normal. There was a need for a stronger social code if people were to get along, living closer together in cities. As has happened many times throughout history, political leaders found it helpful to partner with "God's earthly representatives" to scare or coerce citizens to stay in their lane, so to speak.

That was less about morality and more about trying to establish enough foundational laws in order for a society to be controlled, one step away from chaos.

The Beatitudes were more about morality in the sense that we understand that word today. The 10Cs are more useful to authoritarians. That makes it ironic that Christian zealots (and authoritarian politicians finding it useful to manipulate Christian zealots) keep trying to put the 10Cs into public places, but you never, ever see them trying to get the beatitudes posted.

It becomes obvious when we remind ourselves what that sermon said, because these were very liberal ideas then, and sadly, still are seen as too liberal for most Christians even today. Here is Matthew's interpretation (and there are some variations on these themes in Luke):