Because to publish in a real journal, you typically need both novelty and for your work to be "interesting". The job of the abstract and introduction of a paper (where the word "novel" normally lives) is to sell the reviewer that the paper should be published and to sell you that you should read and cite it.

If your paper is scored / gated on "novel factor" by admission committees, then applicants will over-use that term.

There are a number of papers which aim to improve the attention aspect of models, all being some derivation of the original "Attention is All You Need" paper. A pattern of "'blank' Attention is All You Need" has emerged

This is not new at all, by the way. Bringing novel ideas and techniques is kind of the whole point of research, and explicitly describing what novel thing you did is a good thing to do in an intro/abstract.