Devi

The plugin Changes wordpress user slug for security reasons, it prevents access to the usernames of registered users on your site.
By using “Simply Change Author URL” The WordPress default users(authors) Slug and URL addresses will be changed automatically.
By Default Author URL is: <code>example.com/author/[username]/</code> 
after install this plugin URLs will be changed to: <code>example.com/user/[user_id]/</code>
This will protects the usernames from being easily accessible by cyber attackers.
This plugin also: 
1. Removes wordpress api user endpoints. (they contain information about users) 
1. Changes canonical links generated by yoast.

Simply Change Author URL

Changes wordpress user slug for security, it prevents access to the usernames of registered users on your site.

Brandon Allen

This plugin allows full control of your user permalinks, allowing you to change both the author base (the ‘/author/’ portion of the author URLs), and the author slug (defaults to the username of the author). You can set the author base globally, or you can set it to be user-specific based on a user’s role. You now have the power to craft the perfect URL structure for you Author pages.
WordPress default structure http://example.com/author/username/.
Edit Author Slug allows for http://example.com/ninja/master-ninja/.
Using a role-based author base would allow for http://example.com/ida/master-splinter/ (for an Administrator Role), or http://example.com/koga/leonardo/ (for a Subscriber Role).
Development of this plugin takes place on <a href="https://github.com/thebrandonallen/edit-author-slug/" title="Edit Author Slug on Github" rel="nofollow ugc">GitHub</a>. Pull requests are always welcome!
Translations should be submitted to <a href="https://translate.wordpress.org/projects/wp-plugins/edit-author-slug" rel="nofollow ugc">Translate WordPress</a>.

Edit Author Slug

Allows an admin (or capable user) to edit the author slug of a user, and change the author base.

Simply Change Author URL vs Edit Author Slug