I too do not do well in a group situation with all it's dynamics and different personalities, each with their own agenda. Often there is at least one personality within a large group who seem to enjoy subtly disrupting a meet up in some way...
I've tried, been snubbed, sniggered at, watched the dominant personality take over a lot of the time, been left out, observed cliques leaving people out...it's not for me. It used to upset me, but I do 1:1 friendships ok so really do not care any more.
It didn't help that I experienced being bullied within some family situations when I lived at home. It was horrible.
I know someone who is still trying to fit in wearing herself out with a couple of groups of people, usually coming away feeling very different, inadequate in some way and letting the effort of it all drain them. Sad to watch.
A lot of people do things that do not suit their personalities because it's 'what everyone does', thinking something must be wrong with them if they don't join in, desperately trying to 'fit'. When they would be far happier being an individual, being their true selves, having a good time with a true friend, forming a bond and having shared pleasurable experiences.
I think Face book leads people to think they must have a hundred or more friends and go out constantly [with people who probably don't care about them at all] or they are failures. When real life isn't like that, there isn't the time, money or energy to do it all.