In the server-side web world the controller should ideally only receive http actions and call services or fat models. It should have no business logic, only validation and parsing. In the frontend UI world the controller is bound to UI events and communicates those from the view to the model objects. (1).

(1) https://github.com/madhadron/mvc_for_the_web

Though it's probably easiest understood in a non-web world.

The web makes it quite a bit more involved with a separation of client- and server-side state - plus you have a given frontend "framework" in the shape of DOM, which people often leave out of the picture.

This latter necessities the 'escape hatches' in React and alia.