You must always keep your theme and plugins up to date for security and stability of your site. Some of the plugins update most often like almost every week. You can configure WordPress to auto install updates for plugins and themes by simply adding the following one line of code in your theme function.php file.

Plugins Auto Update:

add_filter( 'auto_update_plugin', '__return_true' );

Themes Auto Update:

add_filter( 'auto_update_theme', '__return_true' );