Phoebe lived with Monica, so that’s how she came into the group. Kind of like Joey too.
Phoebe at one point tried to ”ice” Monica out, but they somehow remained friends.
Ross, Monica and Chandler (Ross’ college friend) are the core of the group. Then Rachel joins, who knew Monica in high school, so they all make sense as they’ve been friends for so long.
Phoebe and Joey are roommates that turned long term friends. So while they’re different from the main group, I still think it makes sense. They bring something to the dynamic that I could see how the others find appealing. So I think it is realistic, even if Phoebe and Joey are both unrealistic characters
What doesn’t make sense, of course, is how much they hang out. For the ones the live together it makes sense, but like the start of s2, Ross comes home from China and the first thing he does is bring his new girlfriend to his sister’s apartment to greet his friends. Then he goes to see his son. Then he goes home. Like, who would do that after a long journey?
Maybe, I would Watch a new show like that… but I’m getting too old to find the antics of 20 something’s entertaining. I can re-watch Friends and HIMYM, much like I can re-watch Buffy or Sabrina. Because I remember it from back when.
Now teen shows and young adult shows fail to grab me. The actors look like children and I, for obvious reasons, don’t relate to their emotional drama.