Of course they know the UI doesn't really do what you want. But they also know they make more money when it's filled with manipulative anti-patterns.

Companies love algorithmic content because because it's the ultimate shield from criticism. "Don't blame us for bad content! It's just the algorithm and we can't control it! Maybe if you interact with it more it will give you better results." Or course in practice it means they have plausible deniability when they shove a stream of ads in your feed.

The one that kills me is on YouTube: "show fewer shorts". fewer than what? Why isn't zero an option? It just means they will shove them in your face again and again. Don't want them at all? Too bad! We need to increase metrics so the PM of shorts can get their promotion!