IMHO, at least the abruptness of the cuts (trimming off all silence between clips) is intentional, part-and-parcel of the aesthetic being demonstrated. Weirdcore is abrupt.

I don't know about the rest — might just be the video's author's style — but I have a feeling the high speaking speed is there because they're mostly reading a definition off of this article (https://aesthetics.fandom.com/wiki/Weirdcore), with no content editing to compress for time, but still a need to make the video feel like it's not "dragging on" for viewers who are impatiently waiting for visual examples. (The proper thing to do here would have been to do the content-editing of the script, of course.)