Case can have information in it, like color and underline and boldface and italics can carry information. I think it would be clever if Google let me colour my search text and then only found text which was rendered in the same colour, but terrible if colouring my search text was mandatory and it then only found pages with text in the same colour. Likewise terrible if your code editor searched only for code with syntax highlighting matching the colours you typed in the search box.

Dog in bold, italics, red, green, uppercase, lowercase, initialcaps, smallcaps, are all the same word. What "the same" means has fuzzy boundaries and sometimes needs very precise specification, but I personally want the default to be the fuzzy convenient and the hyper-literal to be available as a fallback.

[I notice that I used 'color' and 'colour' here. My native language is UK English and programming languages and much of the internet use US English. I'm not sure if I would want `vim colour.txt` to open `color.txt`. Probably not. PowerShell 7 has a suggestions feature for "you typed a command which wasn't found, here are the most similar command names:" - mentioned in https://github.com/PowerShell/PowerShell/issues/10546 ]

> Dog in bold, italics, red, green, uppercase, lowercase, initialcaps, smallcaps, are all the same word.

But that is a feature of the word Dog, try the German words maßen (limited amounts) and massen (large amounts), historically they share the same upper case rendering MASSEN. Now someone versed in German could change to the alternative MASZEN or use the rather modern upper case version of ß. However the default naive (and most of the time correct) conversion between cases looses a significant amount of information.