When Harry Met Sally is a romantic classic and honestly I understand why it’s a super classic.
The plot explores the idea of “can men and women just be friends?”. The story is basically driven around that concept. The entire story both characters are charming, cute and somewhat realistic. Both characters are annoying and have significant bad points when they are younger but both mellow and grow out of their points after long lasting relationships in their mid 20s. But they both find each other serendipitously over and over again (which I admit is the significantly most implausible part of the movie).
Billy Crystal and Meg Ryan are both charming and quick witted. The movie also introduced a few major concepts in dating (“Rebound guy” and “high-maintenance”), at least that’s from Wikipedia. The speech at the end is very cute too.
Also it has the famous Deli Scene, one of AFI’s 100 quotes. It seems a lot of the famous parts of the movies are actually from Ryan and Crystal themselves with a bit of originality and structure from Nora Ephron and Rob Reiner.
Spoilers a bit
The only issue I can see with the movie is that you KNOW it will end with them together, it has to. So it’s just a matter of WHEN rather than a matter of if. So it’s a bit unsettling on that hand because through all the posturing and etc you know the answer to the question. The movie is more about HOW they get there and how they talk about relationships rather than the actual ending though.
The answer though seems to be basically that all the married couple who talk about their relationships in the movie are basically love at first sight or talking with each other and breaking up but basically NONE of them start friends, only they start friends and they basically end up together.
So the answer to the question I guess is that the men and women can’t be friends because sex will get in the way but most relationships don’t start out as friends but all those seem to have ended happily?
I’ve read quite a bit of articles about how friendships into relationships are always tricky and troublesome because unlike When Harry Met Sally, those attractions are one sided (Referencing Sex, Drugs and Cocoa Puffs and quite a few reddit posts).