Who's "we"?
At least here in the US, >60% of the voting public are Facebook users. So we're not talking about "a significant portion" - we're talking about the majority. You sound an awful lot like someone trying to claim that "you know what's best for us".
I think it's clear that Facebook on the whole has detrimental effects on society.
I don't think this is clear at all. Rigorous evidence please! And not "oh look this bad thing happened" - because if that's the standard of evidence then we should ban cellphones, airplanes, riding lawn mowers, and chewing gum.
My post was pointing out a flaw in your stated reasoning. Specifically your over reliance on the fact that the majority wants it without any supporting arguments that this is a case in which the majority will ought to prevail. I was not taking a position on any issue. I’m certain that if you were sufficiently interested in the topic you could find studies showing detrimental effects of Facebook. A search engine will provide you with links.
The “we” is obviously society.
I think it's clear that Facebook on the whole has detrimental effects on society. It does have benefits for people but it has very bad negative consequences for society. Therein is the conundrum. I have no solutions to the problem but also won't discount regulations on Facebook simply because people like certain features.