Some time ago, I saw a video in which it was suggested that a lot of very short living and small creature don’t have the ability to feel pain since they don’t need it to navigate the world properly (It’s the same with plants, who did not evolve the ability to feel pain, having no need for it since they can’t move) being so short of life, having other ways to better ensure the survival of the species.
A lot of larger and more longer-living animals, including us, developed the ability to feel pain as a way to learn. We feel pain as a way for us to learn to better interact with the world, preventing us from dying too early, steering us away from further danger.
This is profound spiritually. The material world is a reflection of the higher, more perfect, spiritual world from which all things arise. So, I see this as a sign that pain, emotional as well as sensory, also ultimately serves as a way for the individual to learn, so that they are guided onto the right course.
Pain exists to give understanding of what to avoid.