That would make sense if we only had a few friends. If you have a few hundred, you only see a small percentage of what they posted, regardless of your actions. Now I understand that my actions impact what I see, but I'm pretty sure it's way more nuanced than what you describe: what does it mean "like that"? I may like or read two posts and discussions about food, and Facebook infers it's about food, but I actually just liked the pictures of broccoli and don't want more food articles. I didn't curate anything, i just wanted to see the damn broccoli.
It's not "me" who decides what I see. I may just want the damn broccoli, but it may take a year or two before Facebook's AI figures that out. And I sure as hell will never figure out what THEY inferred about my preferences, because there isn't any "here's what _you_ decided to see" list that summarizes my inoccuous choices...
How many signals go to the feed? How many of these are my conscious choice? And I am what you could call an expert computer user who actually worked for one of those big tech companies so I can at least imagine some of that complexity and reason about it...