Memes

No it's like saying a person-shaped cloud doesn't exist.

To describe it as person-shaped is subjective and another viewer may describe the same cloud as butterfly-shaped. Because it's a subjective interpretation of a static objective object. Like abstract art.

People/animals exist and are "real" in that all of us have agency and a sense of self that is not conditionally dependent on the identical perception of others.

A person-shaped cloud is only "person-shaped" if viewers claim it is. An arrangement of viewable disparate stars is only "Orion" because the Greeks, and now us, decided it was. But I am me and you are you regardless of what anyone else thinks, and always will be.

We aren't a collection of particles, we are more than the sum of our parts. We have agency and a mind and self-identity. A cloud or a star constellation has none of those things. They are inanimate unfeeling objects that only gain meaning, (astrological, imaginative, or otherwise) when humans/sentient beings ascribe that meaning to them. Human beings, and all living things, have inherent meaning because of their sentience and inherent uniqueness. Which is why genocide is a greater loss than the destruction of a rock - it's the permanent death of unique living beings.