Friends is totally unrealistic but can be very funny. I enjoy it like chocolate. Not nutritious but easy to eat. There's usually a good combination of physical, situational and verbal comedy. From a writing point of view, I think it was quite an achievement to consistently write six characters' storylines and give each of them a pay off in twenty-two minutes over what seems like hundreds of episodes. None of the characters ever really takes precedence over the other and that is a hard thing to accomplish. Having said that, I find the scripts quite brutal - the storylines and jokes are set up and played too rapidly. There's not much to savor.
What irks me most about Friends, other than its constant repeats, is that is has very, very, very little to say about anything. it's empty entertainment.
By the way, I teach EFL and one of the most popular and well-respected textbooks, Headway, includes an article on Friends and its influence of the English language, for better or worse, in its promotion of the word 'so' as an intensifier. Which can be, like, soooo annoying. But that's language for you. It's always , like, soooo developing.