It may be because there in reddit, there generally are more comments to a thread and newer threads faster. The people who respond to the older threads are generally more likely to be assholes. Maybe it has to do with the type of people who browse them, or maybe it has to do because of the people who’d rather follow profile histories to gaslight someone than participate in the community, or maybe the fediverse really is nicer because it doesn’t thrive on engagement thus avoiding the need to artificially create conflict. Who knows.