I think Phoenixes should exist. The reason being that they would be extremely rare and uncatchable. They would appear in the sky as people watch in awe driving their brains to believe that there is much more mystery and beauty in this world. Unimaginable things, unseen and untouched that must be discovered and preserved., It would be a sign of hope. Maybe finding a phoenix feather or down could provide a cure for any types of diseases BUT if people try to monetize it it would vanish. It could be burned and released into the air and as the particles expanded throughout the atmosphere anyone who breathes it in will be cured.