There are lots of situations where you have no choice but use Facebook. Some schools, for example, communicate through Facebook groups. Your church might do the same thing. You may have relatives abroad you can only talk to through Facebook or WhatsApp, because that's all they know how to use. Your landlord or employer might demand to see your Facebook profile as a condition of getting a lease or a job.
The stance of "just opt out of stuff you don't like" bakes in a lot of assumptions about your position in the world, and trivializes real criticisms of Facebook by people who do not have the same choices you enjoy.
I call BS. Every situation you mentioned exists because people passively accept the situation. Simply demanding a method to communicate other than Facebook can remedy the situation.
I'd love to see a list of companies that require a Facebook account. Not ask for Facebook account, require Facebook account.
"You may have relatives abroad you can only talk to through Facebook or WhatsApp" They can't pick up the phone?
Who else do you expect to have the best view on the utility of not using a Facebook account other than someone who doesn't use it?
I don't have one. I don't miss it, and am increasingly glad. But I do have the "spouse firewall"; my wife uses it and I get most of the news I need through that, and even by local standards I'm not really a social butterfly, so between the two things, my experience may not be 100% relevant. So there's my science-style "why this data point may not be relevant" disclosure.
But it certainly isn't a "requirement for modern life" or anything. The times I faintly regret maybe not having a Facebook account are separated by many months, it's not like every day I go to do something and alas, my life is degraded because I don't have a Facebook account. It's a rare event, such that I could pretty much recite to you every one from the past 5 years. (All of them are family news, either get-togethers I wouldn't have heard about, or some family news that I ultimately would have heard anyhow and didn't have any action items on either way.)
(There's enough people without a given social account that I'm still yet to encounter the site that only has Facebook authentication. I hear they exist, but they haven't naturally crossed my path yet.)
Landlord/employer thing you will have to pull an example as that seems unheard of and an invasion of privacy. Obviously don't have a beer bong in your profile picture, but they aren't going to grab your wrist and make you log in during the interview. Landlord has no business knowing anything about your life beyond whether or not you can pay rent.
All those other situations existed before facebook too, and people still got to reunions, went to church, and talked to their relatives living half a world away. Chances are, these people are signing into facebook with an email address or telephone number, so it's not like facebook is literally all they know unless grandson set up grandpas account (but I bet grandpa still has a landline, forwards nigerian prince emails, and writes letters just fine).
The stance of "just opt out of stuff you don't like" bakes in a lot of assumptions about your position in the world, and trivializes real criticisms of Facebook by people who do not have the same choices you enjoy.