What are the differences between Drush 9 and 10
You can check the difference here https://github.com/drush-ops/drush/compare/9.7.1...10.0.0

As you can see, they are mostly fixes and improvements. 

There are also some compatibility changes:


  
  Source: https://docs.drush.org/en/master/install/


As long as you're using PHP 7.1+ there is no risk. The benefit is that it will still work once Drupal 9 comes out later this year.