From never ending, ongoing groups, like family, friends, clubs / sport teams or work to temporary and occasional groups dedicated to events like birthdays, travel with friends, festivals, etc.
The concept of groups is easy to grasp and it's much simpler than organizing Facebook in a similar way. It includes people who don't have a Facebook account (all they need is a phone number and even grandma can join in) and participating feels much less public than posting anything on Facebook.
Of course I imagine Facebook won't mind that transition and development all that much.
Regretfully, this was not the case for me. I tried tweaking my news feed to my preferences for multiple years and it still showed me crap that made me sad. More importantly, mindlessly scrolling my news feed was a time sink, and I found it very difficult to stop. I was definitely addicted to it, in the same way that I experienced addiction to chocolate to cope with my PhD.
I broke the addiction for myself by using a news feed blocker recommended by a friend. Recently, I deleted all the content off my facebook in the hope it would discourage other people from interacting with facebook. The addictive properties of facebook are all in instagram, even if it is less toxic, so I hold it in similar disdain.
If you have that friend on FB then, because he sometimes posts things about cars and it gets heated, that's what FB like try for you to engage with.
FB seeks and promotes "engagement" over "quality of experience" so it will always try to make you anger (it leads to more engagement) than to have a fulling experience.
If the algorithm can only work with chill people and very alike... it will still try to find what divides and "engages" that group of people.