What's the point of using Presenters in Ruby on Rails?

Question

Ruby on Rails

For example, if I can shove all the controller processing into my service object, then why use Presenters?
Example:

def index
  @todo = Todo.new 
end

The Todo class is a service object that contains the processing of an action, and I will insert data into the view through this object.
QUESTION: if you can do this, then why use Presenters?

Answer 1

Presenter - pattern

Answer 2

Service Object (aka Interactor, aka Use Case) should not have the slightest relation to the view layer at all - they exist at different levels of the hierarchy.
Read Clean Architecture.