You never wonder “why am I seeing this and how do I make it go away?”
I actually find myself wondering this a lot. Mastodon doesn’t allow people to add comments to things they’re reposting, so you’re left guessing as to why they elected to insert something from an unfamiliar account into your timeline.
Mastodon is also short on tools for discovering interesting new posts and accounts that aren’t already on your radar. In this regard I agree that it’s behind the times. Threads handles this much better, giving you a classic chronological feed of people you’re following plus an algorithmic feed that shows you things that are popular with people like you.