You left out a key qualifier: CR/LF is the semantically correct way to represent a newline on a physical device that has a physical carriage that has to move back to x=0 and advance one line in the y direction in order to start a new line. What devices connected to any computer today have that property? Answer: none.
In fact, even on computers that have such devices connected, the semantic meaning of "newline" in any file the user actually edits is most likely not to actually cause a CR/LF on the device. Word processing programs for decades now have separated the in-memory and on-disk file data from the data that actually gets sent to a printer. So the file you are editing might not even have any hard "newlines" in it at all, except at paragraph breaks--and that's assuming the file format uses "newline" to mark paragraph breaks, instead of something else.