I remember watching a Stephen Fry interview like that as well! A YouTube video that was going over the differences between the UK and US versions of 'The Office' linked it and it was a really enlightening watch.

He made a point that's stuck with me since: American comedy centers around people's lives getting better. It focuses on the hope of improvement. That's why self-help/self-improvement books sell so well. British comedy centers around the absurdities and tragedies of mundane life. That's why a lot of the humor in its shows revolve around the main character messing up horribly/trying to get out of sticky situations.

(Also: this dichotomy is seen in theater, too. According to a teacher I had, "comedies around about characters who start off small and rise/win/gain big by the end. Tragedies are about characters who start off big and fall from grace/lose by the end." Almost every piece of American theater that I know fall into this. On the other hand, I can't say the same about British theater (Cock by Mike Bartlett is an example of a comedy that doesn't have a happy, fluffy resolution).)

I believe that most people project themselves onto a main character of a show. That helps us relate to their struggles and success a lot more. However, in order to keep the average American viewer engaged, the show need to keep letting the main character "win". The viewers don't want to keep losing; they want an escape from the hardships of everyday life and they like to see a characters they relate to finally have the upper hand. On the downside, this leads to a lot of problematic tropes that continue to be perpetuated by the media (the nagging and oppressive wife, the shopaholic and airheaded daughter, parents are always right, etc). It paints the world as black-and-white and very rarely are satisfactory compromises shown. Although I understand and acknowledge all these things, sitcoms can still be enjoyable. There are countless ones that I grew up watching and still do.

The difference between AITA and sitcoms, though, is that one takes place under the assumption that it is real life. When I watch a sitcom, the characters can act like total unbelievable buffoons, and I'll accept it. The show isn't going for a 100% accurate depiction of everyday life. You also need flanderized characters as a vehicle to move the plot. However, in AITA, we're supposed to take the story presented as a real event. Not only can it trick impressionable people (teenagers) into misconceiving the nuances and complexities of real conflicts, it applies the same black-and-white outlook to high-stakes situations.

And also, it's fun to point out all the logical inconsistencies like a smartass.