I’m not sure if you’re trying to say that more people have watched a particular episode of IASIP, or a classic action adventure movie from a very popular film franchise?
Yes, that's the question. It may seem obvious that it would be the latter, but Raiders of the Lost Ark is nearly 42 years old at this point. Today do you think more people have seen Citizen Kane (1941) or Bambi (1942) as Raiders of the Lost Ark (1981)?
Granted, It's Always Sunny in Philadelphia isn't as popular, and not everyone who has seen one IASIP episode will have seen them all, but the target audience is similar.
People don’t have to watch the entire Indiana Jones movie to see that particular sword scene.
The IASIP scene is no where nearly as viral as the Indiana Jones scene anyway. The Indiana Jones clip has higher production value, there’s no talking, it’s shorter, there’s excitement, and a good payoff at the end of it, it has all the ingredients for it to spread across the world no matter what language you speak. It’s timeless, and always relevant.
IASIP drags on, and focuses on school shooters which only resonates with American audiences. They also basically “explain” the entire joke, vs Indiana Jones which simply illustrates it very well.