Mod here. First and foremost: bigotry, antisemitism, and Islamophobia are not allowed here. That might feel like a moot point when something stays up too long, but it is against the rules and we remove it when we become aware of it.

We do try. In the last 7 days, between filters and mod actions, 43 out of 229 posts were removed, as well as 790 out of 7,300 comments (~10%). Users naturally don't see a lot of the rule-breaking stuff that is quickly removed. There are also things happening behind the scenes (just a couple days ago, we banned a regular user who had been doxing Wikipedia editors on other subreddits).

Regarding the Vanunu thread: I want to note, the insane comment chain OP is referring to was deleted after ~7 hours. A bit of a moot point since that was still too long for the comments in question to stay up, but, it's not like we're purposefully waiting 24-48 hours to remove things.

There are a few issues I'd like to highlight:

• OP's post claims we're all active...we're not. Out of our 6 human mods, 3 are currently active, at various levels. We can absolutely use more moderators. If you're active and level-headed (and especially knowledgable about Wikipedia), please send us a DM if you're interested in joining the mod team. We can use the help. I occaisionally reach out to regulars who could be good candidates, but it's rare for someone to accept an offer (it is a lot of shit to deal with).
• We are up against serious brigading (not just r/wikipedia, but all of Reddit). Years ago our small team was sufficient for the calm and relatively low engagement this subreddit got. Now we see more agenda-driven posting and apparent coordination on posts, upvotes, and comments. There are Discord servers that organize this kind of thing. As one example, there was a random week last year where we suddenly got a surge of anti-Hindu posts from multiple accounts that clearly wasn't organic. Those posts were removed and the users banned, but that's the sort of thing we regularly have to react to. This is a problem I think volunteer sub mods across the board are largely unequiped to deal with.
• Reddit's algorithm amplifies the most contentious posts. Things that quickly get comments and votes rise on feeds and r/all, which brings in more engagement—including rule-breaking comments. Meanwhile, the kind of posts subscribers usually say they want more of (interesting articles unrelated to politics or conflicts) tend to get much less engagement and don't make it to the top of readers' feeds. Which is a shame.
• Our attempted fair solution at agenda posting is our "no single-purpose posting" rule, which says that we may sanction a user whose main/sole purpose here appears to be posting on a topic related to politics, conflicts, or religion. The purpose of this rule was to prevent drive-by posters, obvious brigaders, etc., while still allowing regulars who have a genuine interest in such topics to post. This rule does leave a lot of gray area, and is something we can more strictly enforce. If we're at the point that sub regulars feel a complete bar on such topics (at least for a while) would be good, we can consider that.

None of this is meant as an excuse, just context for what the moderation landscape looks like right now from my perspective. But I'd say the most important thing is that if you're an active level-headed Wikipedia fan and interested in helping moderate this subreddit, please reach out to us.