you assume the cause is facebook, when in fact facebook is the effect of a sick society.
but, facebook does help in bringing to light our abysmal failure in building society.
In essence you can look at facebook as a platform for information warfare. It tends to amplify lies, and some forces are more able to exploit that.
Ultimately though i agree with your point which means even if i am right in thinking Facebook accelerates and encourages bad practices - it doesn’t matter because responsibility lives with each user, each individual.
My suspicion is that we had built up guard rails that were somewhat effective in mitigating against the vulnerable falling completely into the cracks. We should have been doing better, but they were somewhat effective.
I do think you’re spot on that one of its issues is that it encourages other vulnerable folks to join the path leading over the edge. And it makes it significantly easier for the predators to lure them.
While all of us would like to believe we’re special, a large part of who we are comes from our inputs, while a lot of us are careful to vet what inputs we allow to plug into us, many of our people are absolutely not careful whatsoever–many are absolutely and thoroughly addicted to outrage (picture how many people we see who are constantly outraged about something which will never impact their personal lives whatsoever), combine that outrage addiction with the ability to weaponize mis/disinformation, and then combine this with the fact that everyone now has a megaphone, and then combine this with the fact that platforms like fb want to amp up that outrage addiction in order to secure it’s place on these people’s input hierarchies—take all of that, add in a mess of other pressures such our society’s refusal to address very real problems, and we can start to get a small glimpse of the ways in which fb’s algorithms are causing major problems.
And with regards to groupthink, there is surely some basic level of personal burden arising from the freedom of association.