You make Facebook a healthier place by reducing connection and reducing velocity. The things that Facebook will absolutely never be willing to do.
You reduce connection and velocity by ending feeds that show you most of everything, and switch to making people manually seek out what they want to get updates on. People will overwhelmingly be inclined to seek out updates and connections that they get enjoyment from, rather than having agitation/reaction/trigger porn shoveled on their heads all day long.
Tear down that wall.
This would ultimately be labeled as encouraging echo chambers / bubbles. People are typically happiest in their own bubbles, and certainly the majority of the time. That was true 20 years ago. It was true 50 years ago. It will always be true.
If you make a very far left liberal type watch nothing but FoxNews as their information source, they will not enjoy it. That person is going to be happiest, by a dramatic margin, in their own bubble, swimming in their own worldview. That isn't a defect of humanity, it's perfectly ok. It's healthy to enjoy swimming in your own beliefs. People will not all agree with each other, what matters is civility, not agreement.
Stop being psychotic authoritarians and trying to force people to exist in a way they do not want to, an unnatural way. People want to live in their echo chambers, whatever that chamber happens to be. It's healthy to prefer one's own echo chamber the majority of the time (and yes, it's occasionally also good to step outside of that echo chamber). Stop trying to control them, let them live as they see fit (so long as they are not attempting to harm others), as they are happiest.
Stop pushing connections that should not exist. Not all people should be connected. Not all people will get along. Not all people will like each other. Not all people will agree on ideology/beliefs/whatever. That's perfectly ok, it's best that some people are apart, including friends from the distant past who may not like each other in the present. Facebook does the opposite and attempts to drive everyone to be connected, which was more or less their original mission. That's a mission that can only cause strife. A thousand friends? Bullshit. That's fake. That's 950 people that will just largely be annoying at best, with feeds you'll derive very little value from (or negative value). It's obvious what the outcome inherently has to be in quasi forcing so many fake connections.