Why can't we use static objects?

Why codeigniter does not support static use of an object, or is there any to use static method i may missing?
Example:

PHP Code:

// the way we do is this
$this->input->post('username');

// can we do like this?
Input::post('username'); 


Or can we use any helper? like

PHP Code:

post('username');
view('profile', ['username' => 'rakibtg']); 


Thanks :=))