Well, if that commenter had more than just a vague idea of caching and/or swapping, they would know that the right algorithm can make or break performance.
That paper is not “we invented caching”, but “this is how we make some certain models work well despite constraints imposed by RAM and flash storage.”
It’s a worthy job for an engineer or researcher. Not quite as innovative as the invention of the wheel, but still enough to write a paper on (and read it, if you can manage to understand it).