Elemental Support was why Amon had Wu Lang, who had an element weak against metal, in a team against Hu Ti. His purpose in the team was not to fight Hu Ti but to support Yang Li.
While almost every cultivator knew about elemental strengths and weaknesses, many common cultivators like Dao Se were oblivious to elemental supports. The students of the Royal Academy were, of course, taught about this topic in the theory class.
Each element could support another element. Wood supported fire, fire supported earth, earth supported metal, metal supported water, and water supported wood.
Pulling off elemental support wasn't something that could be done simply by knowing. If the two cultivators attempting it performed their arcane arts normally, the resulting arcane arts would simply behave as if they were executed by two conflicting parties, where the stronger art defeated the weaker one. For example, Yang Li's fire would have burnt Wu Lang's barbed whip instead of merging with it.
