The octet rule is a pretty old and simplified model for chemical bonding. It is only applicable for second- and third-row main-group elements in the first place and even there you‘ll find many exceptions (for example: borane clusters, pentacoordinate carbon atoms). Still, many small molecules and most organic compounds follow the rule, and since it is easier to learn than the modern, more accurate bonding concepts, it is still widely taught.

Current research on chemical bonding is done with either molecular-orbital theory or valence-bonding theory, which are both based on quantum mechanics and were introduced in the early 1930s. Both theories have no need for an octet rule, and they are much more complicated. Sometimes, researchers still study whether a molecule obeys or violates the octet rule, but since 1) the concept has become redundant, and 2) many exceptions have already been found, this is no longer an exciting field of research.