There's something special about silent comedies (read Kerr's THE SILENT CLOWNS and see all the classics). They are more akin to cartoons. When sound came in people had to act "real." There was a loss of exaggeration. Exaggeration helps comedy and creates a greater comic effect. The more realistic a person is slipping on a banana peel, the more you run the risk that the audience will empathize with the person and not laugh at the fall.
It's also funnier if someone pompous and dressed in a tuxedo slips on a banana peel. That's funnier than a clown doing it. The clown asks for our laugh. There is less incongruity -- it is more expected -- when a clown slips.
Mel Brooks once said, "Tragedy is I get a tiny paper cut in my finger. It's really small and you can barely see it but it bothers me and annoys me and that's tragedy. Comedy is you fall in an open man hole and break your neck."
Mel's point (and his delivery of it is classic) is that we laugh at disasters happening to other people. The average person would not empathize with the tuxedo-dressed gentleman. Or think the man putting on airs deserved the comeuppance that came his way.
It was an important aspect of Chaplin's character that he always took himself seriously. Note that: Great comedians take themselves seriously. They are playing Hamlet. Chaplin may have been doing funny things, but you get the sense always that he regarded himself as far more than a poor buffoon. That he was something of a put on made him funnier.
Standard prat fall scene. Establishing shot of the banana peel (and it can refer to any trap awaiting our comic hero). The audience expects the fall to come, but still laughs. Keaton did these types of gags with a new spin: Let the audience in on it, and then cross them up. Greater incongruity (for example in the classic finish of ONE WEEK).
Must a comedy writer be familiar with all these classic gags to write comedy? No but it helps. It's also a lot of fun.