The combat looks exactly like in F3, especially that cut when raiders attack player's town - blocky and awkward. AI also looks the same, enemies are just rushing towards your bullets like "there's a guy with a machine gun defending this bridge, I should run up to him and beat him with my baseball bat". I hope at least there are no invisible walls around certain objects that stop bullets. There's a NV mod that fixes that, this is ridiculous.
These "invisible walls around objects" are the hitboxes. Keep in mind that the more complex they become, the more performance the game needs. The games are running semi-arse on console already anyway, so adding more complex hitboxes would just make it worse. So yeah, it's not a bug, it's the middle ground.