It might prove helpful to look at humans etc. to understand the things that trigger the topic of beauty, in the sense that you might learn interesting related ideas in greater detail by studying these things. But the detailed conditions of triggering the topic are not necessarily among them, so "What makes humans perceive X as beautiful?" may be a less useful question than "What are some representative examples of things that are perceived by humans as beautiful?". The world gives you detailed data for investigation, but you don't necessarily care about the data, the ideas it suggests might make the original data irrelevant at some point.

Likewise, knowing how people make moral decisions is not at all the same as knowing what the moral thing to do would be. I

Not in any sense that leadds to straightforward empiricism.

Required knowledge about the world:

That knowledge about the world is necessary is not in doubt. The issue is whether it is sufficient.