A motivating scenario could be: imagine you are trying to provide examples to help convince a skeptical friend that it is in fact possible to positively change the long-run future by actively seeking and pursuing opportunities to reduce existential risk.
Examples of things that are kind of close but miss the mark
- There are probably decent historical examples where people reduced existential risk but where thoes people didn't really have longtermist-EA-type motivations (maybe more "generally wanting to do good" plus "in the right place at the right time")
- There are probably meta-level things that longtermist EA community members can take credit for (e.g. "get lots of people to think seriously about reducing x risk"), but these aren't very object-level or concrete
I don't think that a lack of concrete/legible examples of existential risk reduction so far should make us move to other cause areas.
The main reason is that it might be unsurprising for a movement to take a while to properly get going. I haven't researched this, but it seems unsurprising to me that movements may typically start with a period of increasing awareness / the number of people working in the movement (a period I think we are currently still in), before achieving really concrete wins. The longtermist movement is a new one with mostly young people who have reoriented their careers but generally haven't yet reached senior enough positions to affect real change.
If you actually buy into the longtermist argument, then why give up now? It seems unreasonable to me to think that we haven't yet achieved concrete change and that we are very unlikely to ever do so in the future.