How to redirect page to specific url?
Use a default parameter (for example blog_id) in your routing.yml file:

mymodule.route_name:
  path: '/blog-landing/{blog_id}'
  defaults:
    _title: 'Show blogs.'
    _controller: '\Drupal\mymodule\Controller\BlogController::viewAction'
    blog_id: 'all'


If the blog_id parameter is omitted the default value ('all') is used.

After your edit:

If you are redirecting via the RedirectResponse() class you should call the send() method in order to redirect.