Lots of thought we have is grown and more like a self discovery along your own path.
Generic concepts, which have been thought of by plenty of others are easier to grasp.
Like I thought about things until my sister gave me the word for it: nihilist.
Understanding nihilim is still different than coming to the conclusion of nihilism.
But plenty of other people draw their lines somewhere else. They don't follow philosophy because it's just not important for them.
Or they made their peace long ago.
Your example with creativity doesn't fit my world of nihilism at all (I wouldn't down vote it).
So we are not aligned at all. And you / we are probably not aligned with lots of others on spiritual concepts.
Im thinking about something similar to creativity: we are now so many people with fast interconnection in between us (internet, video) and the general though of something new that it's just a logical consequences that we need to explore all boundaries around us.
I also have plenty of counter examples which did not gave a reward for being creative from 'the universe's.
Being an artist is not easy.
Your thshirt example is also more realted to capitalism. The original motivation is getting money for food.
Those systems / constructs are not made by the universe they are made by us. Those are our constructs.
We reward creativity due to the desire for new stimula.
This goes more into machine learning or game theory: how to train a network to create an image? By creating a counter network checking if something is not an image.