Most of Western cuisine is derived from classic French fare. Auguste Escoffier’s modernisation of classical French cooking techniques serves as the base of the culinary world today, in particular, his popularisation of the 5 mother sauces:
Even with more sauces being created for Western dishes these days, it’s not hard to see that the mother sauces are the bases of those creations. E.g. white wine sauce and mushroom sauce are derived from velouté.
So, whether you’re serving up hearty Italian dishes or Western fusion delights, knowing the fundamental sauce tree is essential.