Well, the website and mobile app are overwhelmingly hated (just look at the reviews on the PlayStore). I think there are two major things helping Reddit: It’s easy to grasp (Lemmy has instances, dozens of different apps, etc.) and the fact that Reddit already has a community for basically everything.
Ruby was designed to evoke joy and they absolutely succeeded. Usually, programming is mostly a means to an end to me. But using Ruby just feels so amazing, it’s almost impossible to even describe to somebody who has never used it before.