1 In the Aristotelian world things are divided up neatly into subjects that could be studied independent from each other. Chemistry has no connection to tragedy, physics has no connection has no connection to theology. But anyone who has studied multiple subjects starts noticing similarities between the most distant of disciplines. A lot of the same concepts exist in different subjects but with different names. I've mentioned before on this blog that I have an intuition that the "Skully effect" and the "Placebo effect" really come from the same general principal that "people construct stories from stories that they are exposed to" that exists in theology and in hermetic stuff. Another one I've mentioned is "The Power Process" being very similar to the idea that we were "made in the image of God" that exists in Abrahamic religions. I was redoing the file system on my computer a bit ago and had to choose between having large filenames in a simple folder system or having short file names in a complex folder system ― a bit similar between the difference between a highly inflected language and one that is not (English is still the only language I know right now, but I've tried learning bits and pieces from others).
2 I wouldn't say that this fact is even contested even if it's rarely verbalized. Math could not be useful if we could not sometimes pull out things that were similar about the world around us. If math ― as I've heard before ― is the ‘the study of structure’ and we use the same math everywhere does that not mean that the world itself is structurally similar? IQ tests say that abstracting anything well is associated with abstracting everything else well.
3 A lot of this renaming and jargon production probably has to do with people wanting to further their carrier by putting their name on something wanting to "make a mark" and the attention that comes with it. This is pretty harmful I think. I've found that older books on almost any subject I study are much easier to study and read do to them using more general terms. Using jargon when none is needed leads to some associating things that are written badly that they don't fully understand with things that are "smart" ― leads to them also writing less clearly.
4 Or maybe this similarity exits because we are constructing the world similarly and exists because of us as opposed to the worlds generation that exists somewhat independently? Is this similarity tied into the principle of imitation where we are drawing from the stories that surround us? But is that distinction even useful? Anyhow I'm not against organizing the world into topics. I think that it allows for things to be taught more linearity which is necessary when teaching to a group of people instead of just a few. I'll have to give this more thought.