Why use compass watch if sass already has watch?

Question

Sass

Hello. I am learning sass. I saw lessons that say that in order to create a watcher, you need to install compass, create 2 files: config.rb and watch.bat.
In the first settings:

require 'compass/import-once/activate'
Sass::Script::Number.precision = 8
http_path = "/"
css_dir = "css"
sass_dir = "scss"
images_dir = "images"
javascripts_dir = "js"

In the second, the watcher himself:
compass watch scss/main.scss
I have a question. Why all this, if you can just create 1 bat file and write the following there:

sass --sourcemap=none --precision=8 --watch scss/main.scss:css/main.css

It seems to work exactly the same.