I am old, practically senile, and easily bored.
Without getting into all the philosophy (which I never understood) I am an empiricist. The physical world as best we can understand it through empirical science actually exists. Art, for lack of a better term) tickles our nervous system. If we like it, it’s good. If we don’t like it, it’s not good. We all are all the same species, so some of us get tickled the same and there are 7.5 billion of us, so we all tickled a little differently.
My favorite example of “world building” which I must have read over 50 years ago was a story that ran something like this
The last man on earth sat alone in a room. There was a knock on the door.
On a little larger scale, one of the most self ironic literary world building works on world building is Theodore Sturgeon’s MICROCOSMIC GOD. You might be able to find a copy you can read for free on line. I will let you do the work. Time for me to get ready for bed.