You don't want a fb account? don't get one, that's fine!
If you are worried you are missing out on stuff by not having one (this is why people want to add you or contact you via fb?) then you can get an account, but it is ENTIRELY up to you how you use it.
MN seems to have a lot of women very worked up about x y and z on facebook, but they don't seem to be aware that they can control what they see (and can always ignore what they don't like anyway).
People use facebook in ALL sorts of different ways. It's just a tool, there's no wrong or right (well, unless you are makjng violent threats etc - and then that's the violent threats that are the problem, not the social media).
I think a lot of daft problems crop up because social media is still in its infancy, relatively speaking, and people struggle as a result. facebook 'Friends' is just a term, perhaps misleading - it doesn't mean at all you Re bestie mates with everyone you are facebook 'friends' with. Unless that's how you want it.
I think there can also be a gap between how someone is in rl and how they come across on fb - not because they are awful but just because it's a different medium from face to face communication. I know some people who are very quiet in rl and surprisingly vocal/articulate on fb. Some the other way round. I've been surprised to see people posting statuses about being unhappy etc when they come across as happy in rl (and a few times been very surprised and unfriended when people turned out to have racist views I had no idea about on the basis of a casual acquaintance).
Re: boasting and bullshitting - personally, I think the people who claim to see a lot of that stuff are either very very unlucky in their choice of friends, or go looking for it, tbh.
The short version is - it's entirelt up to you, but bear in mind that no social media is an exact 'mirror' of the world around you.