Replace Standard Node Path in Drupal 8
While theoretically now supported, that is not possible not like this.

You can not reliable load a node based on the node title, it is not guaranteed to be unique, and to become a practical URL, a number of replacements should be made, like replacing spaces, lowercasing it and so on.

Use the path alias system for this, just like in Drupal 7. We're maintaining an inofficial port of the pathauto module, that allows you to configure token patterns to automatically generate an alias for each node. You also need token.module, which you can get from here.