Reddit suffers greatly from the lack of quality moderation. The moderators on reddit remove spam or off-topic submissions but more than often leave low effort or just worthless threads up, which in turn invites more people to post similar content.
My favorite example of this is the /r/snes subreddit where most of the new posts seem to be photos of the games someone bought off somewhere. I've never seen anything like this on any old-style forums outside of a thread dedicated solely to this kind of thing.
> more than often leave low effort or just worthless threads up
to be fair, forums do this too - you're just less likely to notice because many forums would have multiple boards / forums where you would post in separate categories. very often, there would be a screenshots/picture forum.
reddit, due to how it's designed, is forced to organize everything under a single subreddit. labels help some, but it's just not the same.
My favorite example of this is the /r/snes subreddit where most of the new posts seem to be photos of the games someone bought off somewhere. I've never seen anything like this on any old-style forums outside of a thread dedicated solely to this kind of thing.