I'm often the person making that argument, so only seems fair I take a crack at this.
> 1. Why is facebook required? (to get right to the
> point) I know MANY of my friends use facebook but I
> still find it quite easy to keep in touch with them
> over email/gchat/texting/in person.
There's a few factors, but let's start with "low interaction friendship". When I log in to Facebook, there's a post from a guy who lives in a different country to me, who I met on a bus 8 years ago, posting about his crusade to stop his vet offering homeopathy(!). I see an update once every two or three days from this guy, but we're not really close enough to send each other regular emails or messages. But last time we were in the same city, I sent him a message, and we had dinner, drinks, and went to a show. I listened to his latest album a few years back, and as a result, we had him play at our wedding. I have a
lot of low-interaction friends like this, and they enrich my life incredibly. I would not have the mental energy or time to maintain lots of friendships like this by email.
I have a reasonably large extended family. We could start up a mailing list, but we're not all related to the same people. When I see them in person, I have been "keeping in touch" because I've been seeing their family photos, seeing daily updates from them, and interacting with them. Again, I don't have the time or energy to do this actively.
We have a party organized this weekend. There are 40 people on the invite list. A Facebook event has meant that we've invited a whole load of people who we might not have invited to a more intimate event, but also that we got suggestions for a bunch of people to invite - we went through our friends list, and often thought "haven't seen Joe in ages! I'd forgotten he was in town, let's invite him". Facebook has kept track of who's coming for us, and will gently nag our guests to reply either way. We don't have cellphone numbers of email addresses for many of these people.
Conversely, a couple we don't know very well has invited us to an event in a fortnight. We're not that close to them, but we can see on Facebook that a whole bunch of our mutual friends who we do really really like are going. As a result, we'll probably go.
Many of these things are possible without Facebook, they're just much much harder, and we probably wouldn't bother.
> 2. Are many people you know actually going exclusively
> to facebook as their sole communication method? This
> hasn't meshed with my experience, but I'm in a very
> limited population strata. As a followup, do these
> people find any difficulties when connecting with
> non-facebookers, since I know plenty of those?
Yes. Facebook Messenger is the primary way I communicate socially with people. If I happen to have everyone's cellphone, I'll use WhatsApp, as it has a few more useful features, and not everyone has Messenger installed, but generally FB Messenger is how I communicate with people, as it's a constant, even when they move country, change numbers, change email, whatever. I ran in to some old high school friends at a university alumni event recently, who I hadn't seen in decades. I added one of them on Facebook, and he created a Messenger group with some other people we went to high school with, and we organized lunch. I could have gotten his email, and we could have done it that way, but I don't think he had contact details for some of the other people he invited, other than Facebook.
I have three ex colleagues who I'd love to be more in touch with, who aren't on Facebook. I try and see them when I am in the same city as them, but I often forget they're around, and because I'm not up to date with what's going on in their lives, we often have less to talk about.
> 3. Is it a conscious calculation for you/most people
> you know? e.g. is there even a thought of "Am I happy
> with the tradeoffs at hand to use this" or is it just
> the accepted dogma at this point.
Not as far as I know. People who aren't on Facebook are the big exception, and they tend to be the slightly kookier people.
The trade-offs seem hard to articulate. I don't feel like my social graph is particularly private. There are plenty of things that I do like to keep private, but Facebook knowing who my friends and family are isn't really one of them.
Anyway, hope this wall of text helps a little.