I agree it's not very pleasant to watch and this style is often abused, but it serves a real purpose in this video. He's making broad points about movies as whole in two different timeframes and comparing between them. When he's discussing a particular movie the shots illustrate which movie (and in many cases which parts of it) he's referring to. When making broad statements about whole clases of movies the shots provide examples of the points being made.
Using shots like this is much more information-dense than verbally listing a load of titles and scene descriptions and triggers the viewer's memory much more effectively. Keeping the clips very short allows more examples to be packed in and also protects against intellectual property complaints. (The need for the latter is highly regrettable but a daily reality for youtubers.)
Using shots like this is much more information-dense than verbally listing a load of titles and scene descriptions and triggers the viewer's memory much more effectively. Keeping the clips very short allows more examples to be packed in and also protects against intellectual property complaints. (The need for the latter is highly regrettable but a daily reality for youtubers.)