Nothing is static and that includes the science and art of SEO. Where once it was all about keyword density, today the same behavior can get a site put on the Google hot seat for keyword stuffing. In fact, the very art of using key words is not what it was. Study shows that out of more than a hundred useful metrics for creating customer interest and enabling conversion rates, keywords were not even in the top one hundred. So, while keywords should not be thrown out, like proverbial baby with the bath, how they fit into an SEO plan may need to be re-examined.
It starts with realizing that Google algorithms are far more sophisticated and able to appreciate what constitutes a more human and natural flow of speech-like text. For this reason keyword stuffing, which was always notoriously stilted is passe. Nowadays, the key to keyword use is not to try and manipulate the algorithm, but to lure in the potential customer with words that engage them and relate to their specific needs.