I wouldn't call it a benefit or disadvantage, but more of a difference: wp_strip_all_tags simply strips all tags (except for the allowed tags) by calling the PHP function strip_tags, after removing script and style tags in full, including their contents. wp_kses does no such thing:

// Returns 'alert( "test" )' (content of script tag)
wp_kses( '<script>alert( "test" );</script>', array() );

// Returns '' (empty string)
wp_strip_all_tags( '<script>alert( "test" );</script>' );

So, if you were to use wp_kses and set it to not allow any HTML, it would differ from wp_strip_all_tags in that it would not remove the content of script and style tags.

I wouldn't call it a benefit or disadvantage, but more of a difference: wp_strip_all_tags simply strips all tags (except for the allowed tags) but does not delete their content by calling the PHP function strip_tags, after removing script and style tags in full, including their contents. wp_kses does no such thing:

// Returns 'alert( "test" )' (content of script tag)
wp_kses( '<script>alert( "test" );</script>', array() );

// Returns '' (empty string)
wp_strip_all_tags( '<script>alert( "test" );</script>' );

So, if you were to use wp_kses and set it to not allow any HTML, it would differ from wp_strip_all_tags in that it would not remove the content of script and style tags.