@cateen @FrostedSiren @Gargron Twitter pushes really really hard for people to follow those who aren't in their network. There are recommendations, and it actually takes effort to avoid those, an effort most people don't expend. I myself use Tweetdeck on desktop and Talon on mobile. Both these clients don't support any foreign items like "%username% liked" or ads in the feed.
@cateen @FrostedSiren @Gargron without recommendations, brands, and other engagement-driven crap, social media is actually a surprisingly decent and interesting place. A bit like forums.