the main purpose of cooking vegetables is to break down the fiber which humans cannot digest and which locks the nutrients in the vegetable. with enough power a blender will physically break down the fiber and thus release the nutrients.

juicers serve the same purpose - they physically release the nutrients which the body can't chemically release from whole plant.

thermal and mechanical "cooking" really serve the same purpose here but thermal is much more crude. it's like the difference between controlled demolition of a building and burning it down.