There's little societal trust in e.g. Russia, and yet they're getting massively scammed by Ukrainian call centers every day. People selling their only housing, sending all their savings for “safekeeping” overseas, are daily news. Not just old ladies (but them too), but also middle-aged intellectuals who were supposed to know better.
It's all using the same schemes that have been explained in the news over and over again, there's little innovation on that front. You have to be living under a rock the for past few years to fall for them, and yet people do. I think there's simply a certain amount of marks in every society, regardless of how its members trust each other, and the only reliable way of protecting them is managing everybody's lives DPRK-style.
I think the only reason of why it works is that Ukrainians are an even lower trust culture, and they are better and more cynical at duping people. Plus, in Ukraine many people see it as their patriotic duty, and perhaps rightfully so, so these kind of jobs are likely to attract quite sophisticated people who will be able to pull off very believable scams, not some social rejects or worse, forced labor sitting in Myanmar jungle, as it is in Asia vs USA scams.