It all started with being sick of being presented with walls of negative stuff (usually political, all sides) every time I went into FB. Not wanting to see that crap I started to put people on 30 day holds. I eventually decided that if I had to put someone on 30 day hold three times in a row I should unfriend them. And that is exactly what happened with a number of people.
After several of those cycles I asked myself a very simple question: Why?
That's when I unfriended everyone except close family (a little over a dozen people). I can now derive some value from FB.
I have a long list of things FB should do to actually be more useful. One of the things that always bothered me was that they force you to toss everyone into one big pile and everyone on that pile is exposed to everything you say and do. Yes, sure, you can group friends and explicitly post to a limited subset. Frankly, the implementation absolutely sucks and is a pain in the ass to use.
The model needs to change to everything being absolutely private and not farmed or captured by FB unless the user chooses to open doors beyond that.
There is no reason for my friends from the gym should have any visibility into my family and my conversations with my family. The same applies to work friends or neighborhood friends. You can accomplish this today but the UX/UI are absolute garbage. A user needs to be able to put people into silos and the software needs to enforce privacy between silos by default. It should take work to pierce silo boundaries. Again, no reason for someone's bowling club members to ever see conversations with family.
I had a case with a friend of a friend who would snap tons of pictures whenever he got invited to a gathering at my house. He would proceed to post all of these pictures publicly on FB --as in anyone in the world could see them. I am not paranoid, but I don't want pictures of my kids, home and family all over the internet for everyone to see. If you are not a parent (and, in particular, if you don't have daughters, you might not get this). I asked this guy twice, politely, not to do that. I explained that taking pictures of people in a private residence does not entitle him to post them for the world to see without permission. I eventually had to pay an attorney to give him a call and get it sorted.
Another interesting issue with FB happens when your friends post stuff from publications you do not care to see on your timeline. They offer the ability to block some people and pages, but there are a few holes in that. I don't remember the details. All I know is that I kept being exposed to garbage from a couple of people and the only way to not see it was to suspend them for 30 days or unfriends them. I eventually just unfriended them. I reached out to FB with the issue. They could not care less.
On the business side, they angered a lot of people with their approach to your audience in groups or pages. I have personally invested tens of thousands of dollars in the past aggregating people behind pages only to be slapped in the face by having to buy advertising to reach my entire audience. Imagine having a page with 100K people you spent money to aggregate and only being able to reach a few percent of them with your updates (unless you pay).
I remember when brands used to advertise their FB pages in TV ads. I never understood why they subverted their amazing brands to FB. Well, eventually they all stopped. You don't see that kind of thing any more. Businesses want to own their audience not have to rent it every time they need to reach to them.
For all the good FB does or can do it also has some dark patterns that they should address.