"...You didn't actually pay attention to Halo's story, did you? Yes, the Covenant is trying to wipe humanity out to the last, but the UNSC never even mentioned the complete eradication of the Covenant species. They're just trying to survive in this case, they're not trying to counter-eradicate the Covenant.
Now granted, the Prophets are pretty much screwed by the end of the series, but that's because they had a tiny population that was mostly living in High Chairity, which was completely overrun by the Flood and then destroyed, but the UNSC never said, "Whelp, I guess we're gonna have to completely eradicate every species to the last individual.""
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Now granted, the Prophets are pretty much screwed by the end of the series, but that's because they had a tiny population that was mostly living in High Chairity, which was completely overrun by the Flood and then destroyed, but the UNSC never said, "Whelp, I guess we're gonna have to completely eradicate every species to the last individual.""