> Editing implementation for single lines of text do not work well at all for entire text files. Operations become incredibly slow, which is why we invented things like rope data structures and buffered views.

memmove() is about 100 gigabytes a second on my computer. That's 100 megabytes every single msec. My screen refreshes at about 100hz. None of my source code files are even 1 megabyte let alone 100 megabytes, so at least on my computer, for all of the files I edit, there isn't a single operation that a "rope" or a "buffered view" could offer over the naive because I could literally just rewrite the entire file in C 100 times every keystroke, and I think for many operations it is obvious how to do better.

For this reason and others I think it's absolutely plausible for a beginner to self-teach themselves how to write a good text editor and even improve on things, and I would never want to discourage someone from a discovery they have both the interest and the time for.