Personally, I think Satipatthana is the essence of all dharma paths, both hina and mahayana.
If you go that expansive: not everyone sits. Morality is the apparent essence of all Dharma paths. But of course the real essence is Bodhi Mind.
There's more to satipatthana than culturing morality. There's also concentration and wisdom. The three reinforce eachother. Starting with minfullness and enjoyment of the present moment, one arouses the thought of happiness, and this happiness is associated with sati. In the suttas, it is said that happiness gives the mind peace. Many teachers, from ajahn brahma to thigh naht Hahn urge practitioners to develope this ability to create happiness by enjoying the present moment, which in turn gets the mind interested and attracted to meditation.