Reddit feels like a weirdly dead place. Depending on the sub, there can be a lot of posts and comments but it's very hard to engage with. You need to comment early and what conversation there is decays very early. A lot of it is fake too, with bots stealing comments to repost.
It's a little bit better on smaller subs, but Reddit has a way of funneling everything into a larger subs if there is one for a topic, so outside of niche topics they tend to be ghost towns.
Lemmy is more like a small, weird forum. It's hardly perfect but at least it doesn't feel like a bunch of chat bots talking to each other.
Starship Troopers is Heinlein not Dick, and it's fascist nonsense. Verhoeven was right to throw the book in the bin after two chapters and the movie rules.