Noticed this on reddit's All/Hot in the last two years or so. Not even just the posts but the comments in particular were very Bot-like. Front page was almost all recycled reposts and thinly veiled marketing.

Before doing Lemmy full time I scrolled through Red with the official app just to see if I could compromise somewhere, but it smelt of Dead Internet to me.

Dead Internet Theory in short is a conspiracy theory that most of the Internet is just algorithms and bots posting back and forth at each other for marketing purposes and to nudge people's beliefs. It's dead because theres hardly any humans posting.