The problem of animal suffering extends much further than pain as mere response to danger. The problem acknowledges the fact hat very sentient creatures spend lives that are often full of misery - not as a bug but a feature. The animal world is a thriving hive of misery most of the time.

You can imagine a higher purpose if you like. That's up to you. But growing numbers of people are admitting to themselves that their ignorance isn't the root the problem - their conception of an all-powerful, all-loving God is.