I have noticed the same thing, my news feed is full of people that I don't even message at facebook. Later I realised that it's because I unconsciously spend more time on their posts because of their clickbaity nature (ex. politics, humorous posts, attractive people, controversial topics) than I do with my real friends. I tried creating a few accounts to test this hypothesis and found out that even if I don't like or comment on their posts, just the act of hovering over their posts for a few seconds longer than other friends is enough for the news feed algo to prioritise these posts on my feed.

Twitter got it right with a "customisable news feed", the list[0], where I could create several list timelines for my friends and organize them by those who post about tech, business, political rants, etc.

[0] https://help.twitter.com/en/using-twitter/twitter-lists