Unfortunately, Facebook mirrors human society and gives bad/profit-driven actors an easier avenue than traditional recruiting and distribution.
Most things are good/neutral, but scale means some things will go south
I'm not sure what you mean here. Do you mean groups on facebook or that there are other groups on the scale of facebook people (ie. a user count in the billions) derive value from?
For the first, in the absence of facebook these groups would no doubt still exist. There were forums before facebook and some of them grew quite large. There were even regional social networks on smaller scales (I worked for one once).
If you mean the latter, well, I don't think that's really true. In so far as it is, there are only really a couple that aren't just owned by facebook to begin with.
I don’t think they would.
Creation, discovery, participation, following. None of these is particularly easy if you revert to forums and Google. I won’t join Cute Puppies Forum but I wouldn’t mind following an homonymous group on Facebook for a little while, maybe I’ll answer some questions too.
The average Joe won’t care enough to join their little city group, but Facebook makes it so easy that you find all kinds of non-tech people on it, ready to answer your questions (and sometimes insult you, but I block those on sight).
Maybe I'm wrong, but again I have to ask the question: Are those conveniences actually worth the harm we see from aggressive narrow ad targeting/tracking, as well as the issues mentioned here around parasitic viral memes, that make things like facebook even viable as businesses?
This is an evaluation we are allowed to make, and it's not a foregone conclusion that just because people can build these things they have a place in our society.
I don’t think we should reduce public liberties because some people take advantage of them. I’d rather punish/limit them instead.
Anyways, no "public liberties" are unlimited. All are constrained where leaving them open creates significant harm or burdens other people's liberties. Even free speech and freedom of association.
People understood that once. "All my freedoms are absolute and who cares if society falls down with them" is a modern construct and it seems pretty plain to me that it's resulted in a lot of problems.