Do you think lemmy/kbin’s relatively poor and insufficient moderation tooling is partly to blame for what you’re seeing?

Not as such. The moderation tools lead to redundant handling, and make it easy to miss reports you shouldn't miss, and force you to leave reports open so that others don't miss them, but the actual number of reports is more of a cultural thing than anything else.

Do you think that the communities based structure make this sort of thing more likely to be bad or problematic?

So, the microblogging fediverse (which I'll call microfedi) existed for years before twitter crapped the bed. It housed queer folk who had left main stream social media, and those queer folk set the culture and ran the instances. So when twitter happened, even though the culture changed, there was a sufficient mass of existing instances to ensure that bigots remained unwelcome in the mainstream fediverse.

However, when reddit crapped the bed, by comparison, the threadiverse basically didn't have an established culture. There was a handful of lemmy instances (we were one of them), but the only one of notable size was lemmy.ml. kbin didn't even exist in any meaningful way until a couple of months before reddit died.

So, when reddit died, there was no established culture. Instead, people brought reddit culture with them, and reddit culture, because of lax admins, was much more tolerant of hate speech than microfedi. And so, people who are "reddit people" more than "fediverse people" set up lemmy and kbin instances, and brought those reddit norms with them.

So then, you get instances like blahaj and beehaw that are threadiverse instances, but have the "old school" microfedi approach to bigotry. We smash it down hard at the first hint of seeing it, but most of the instances we federate with don't attack it so aggressively.

And thus, on microfedi, much of the work is done by remote admins before I ever see it, but on the threadiverse, it's often just not done by remote admins (unless it's aggressively hateful), and that means I end up seeing a lot of shit, and blocking a lot of users that wouldn't have had a chance to get established in the microfedi universe