IMHO, Kanban and SCRUM attempt to achieve the same goal, throughput. However they put systemic pressure on different points of organizational breakdown.
SCRUM takes the stance that communication is where throughput suffers. Without effective communication, via iterative planning, efficiency is lost.
Kanban believes focus is the point of efficiency loss. By moving tasks through work limited stages a team gains laser focus which should encourage high throughput.
That doesn't mean that SCRUM doesn't value focus. It utilizes story points and velocity to encourage tightly focused iterations.
Nor does Kanban ignore communication. Boards communicate work status and well designed work in progress limits on your board should encourage communication and collaboration amongst team members.