If humanity wipes itself out, those wild animals are going to continue suffering forever.
Not forever. Only until the planet becomes too hot to support complex life (<1 billion years from now). Giving that the universe can support life 1-100 trillion years, this is a relatively short amount of suffering compared to what could be.
And also only on our planet! Which is much less restricted than the suffering that can spread if humanity remains alive. (Although, as I write in my own answer, I don’t think humanity would spread wild animals beyond the solar system.)
Not forever. Only until the planet becomes too hot to support complex life (<1 billion years from now). Giving that the universe can support life 1-100 trillion years, this is a relatively short amount of suffering compared to what could be.
And also only on our planet! Which is much less restricted than the suffering that can spread if humanity remains alive. (Although, as I write in my own answer, I don’t think humanity would spread wild animals beyond the solar system.)