I can't speak for you, but I would hugely prefer for humanity to not wipe itself out, and even if it seems relatively likely at times, I still think it's worth the effort to prevent it.
If you think existential risks are a higher priority than parasite removal, maybe you should focus your efforts on those instead.
Serious, non-rhetorical question: what's the basis of your preference? Anything more than just affinity for your species?
I'm not 100% sure what you mean by parasite removal... I guess you're referring to bad decision-makers, or bad decision-making processes? If so, I think existential risks are interlinked with parasite removal: the latter causes or at least hastens the former. Therefore, to truly address existential risks, you need to address parasite removal.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.