Poodles were bread to be cold water hunting dogs. That’s why the traditional cut has large poofs around joints. Over time smaller breeds of poodle were bred for companionship. Neither of these purposes are some sort of frivolous waste.

A good reason to bring back extinct animals is furthering our understanding of biological life and animal genetics. There are other justifications such as carbon fixing, improving of the ecology in thawing tundra regions, etc but those are bonuses to the primary reason I listed. Science, basic science, is the foundation upon which all applied science is built. That is its own justification. Not every act must have a practical and monetizable outcome in the immediate present.