Is Everything We've Ever Learned Emergent?

Everything we've ever learned is emergent. We have no knowledge of the fundamental, and we don't even know if there is something fundamental. Maybe it's an infinite tower of effective theories all the way down. There is no deep truth. How do we know that our tower will line up with alien towers? If they have another way of looking at what you call coarse-grained theories of the universe,. where to me fine-grained could be as small as an electron or as large as a planet?"