You can and
should ask your friends to adapt if FB is the
only form of communication they will have with you.
First off, you're doing a terrible thing to yourself by framing it as if you have only two choices: Become FB's product or become ostracised from your social circle. The latter is a deeply-ingrained biological fear, back in our tribal hunter/gather days, this basically meant death. Advertising has been abusing this biological behavioural function since the early 80's[0] but Facebook is going to extremes by actually invading and parasitising off our current social fabric, rather than just promising a "cool" lifestyle on top, like branding does.
In addition, by letting your friends do this, you are normalising the idea of "FB as only form of communication" for everybody else, too! There's so many people out there who would love to stop using FB that won't because they, like you, deeply fear being ostracised. More than you think (you won't find them on FB). If you feel that, just maybe, a single mega-corporation shouldn't be able to do this to more than 25% of all people in the whole wide world[1], then just maybe it's worth it to take a tiny bit of a stance and have a firm talk with your friends about this abuse, no?
Then there's people that I've seen (on here) crying, "you seem to have it easy, apparently your friends+family will accept this and you have time to find other means of communication but I live far away from home and have no time, and I would be so incredibly lonely if I'd stop doing FB". If you really, really feel that way, here's a big, fat yell-out-loud piece of advice: YOU ARE ALREADY LONELY. BEING A FB USER JUST OBSCURES THIS FACT. START TAKING ACTION TO FIX THIS IN A HEALTHY WAY. You're a user, and your social network consists of users (even if many of them seem to do fine). Ask any ex-addict what that's worth.
Finally, some of my friends have gone through hard times. Money, mental health, bad times. Sometimes they drop off the radar. Damage or lose their phone, disconnect from the social networks because of anxiety, shame or worries. These are the people that need their (real) social networks the most. I (and some of my friends with me) always make a point of SMS texting them about social stuff, keeping them in the loop, hangouts going on, once I realise they no longer read a certain group-chat. Even if they don't reply 4 out of 5 times, you will find they are super-grateful the fifth time. If you love them, keep an eye out for them. And even if you don't know anyone in this kind of situation, somebody you know probably does, so for their sake, start normalising the idea of keeping people in the loop whether they are on FB or not! (same goes for other networks/means of communication, but FB is extra bad because of its ubiquity and it's actively exploiting our human behaviour in a manner that is harmful to many individuals--while to groups appearing fine).
> I've often seen the argument "well if they aren't meaningful friendships, it doesn't matter" but that's just not practical. Sometimes you'll reconnect with someone who you haven't spoken with in 5 years - that's occasionally how friendships work. Friendships aren't permanent and steady in intensity: they sometimes fade in and out. Quitting FB obliterates all those transient and potential future friendships.
Except for pointing out the fact that last line is false and this fade in/out of friendships really does happen whether you're on FB or not, I'm just going to repeat: Ask any ex-addict. There's a lot of subtle nuances and facets to this fear of losing touch with certain people or potential future social contacts if you'd really really stop being a user. Be sure to ask one instead of assuming you know what they'll tell you. If you think you don't know any ex-addicts, try asking about alcohol.
> We can reduce you saying "When you learn how to live without it" to you saying "When you learn how to live without interacting with a decent chunk of people that you know".
But are you really. How can you even say you're interacting with a decent chunk of people that you know if that interaction is forcefully mediated through a singular channel of communication and you openly admit you're unable to really connect with them otherwise.
> Does it seem so easy now?
Face it, what seems hard is actually interacting with these people more, in a way that does not involve using FB together. It's that corporate-manufactured addictiveness talking. Just like the trying-to-quit alcoholic, finding it hard to expand their interaction with their friends to include things that do not involve consuming alcohol, getting pulled back in again every time.
And if you're that far in, you have my compassion. Because that is hard. It starts with facing the facts and not making excuses, it is your social responsibility.
On the bright side, working to expand your interaction with those you care about outside FB, is wholesome and fun. Chances are you might even reconnect with someone you haven't spoken in 5 years.
[0] Naomi Klein, No Logo. With the rise of "branding", advertising shifted from "this is our product" and "it's better because it has Y" towards associating the product with a lifestyle, a social group often entirely unrelated to the product (Coca-Cola being the classic example, having gone through many lifestyle-guises, none of which having to do with consuming carbonated sugary chemical sludge).
[1] 26.1% at time of posting, https://www.wolframalpha.com/input/?i=(facebook+users)/(worl...