Armies of moderators? Mudcat has what...several hundred members,of which a much smaller number are regulars.
FB has hundreds of millions in countries all over the world. Thus, their primary 'mod' is a program to catch a chosen list of no-nos. Even the appeal process is limited, and FB even has a "open a new account" button which lets banned people back in under a new name.

   FB is not a site that can BE fairly moderated. All they can do is change a very complex algorithm.... one that doesn't interfere with their advertising too much.... and they couldn't run such a huge site without selling ads. You take your choice... and like Senoufou says, it can be a great resource for some.

   There is simply NOTHING like FB. One can limit who sees their posts...up to a point. But some 'friends of friend' can intrude. It's like pubs in different parts of town.... some have nicer clientele than others. You get 'mostly' what you came for.