You’ll have to look in the database to see how ACF stores the checkbox values. As far as I know, they’re not saved as flat meta values under a single key, which makes it not possible to efficiently query on that data.
The queries you have now aren’t going to work, you’re just loading a single post in each of them and checking if the field has a specific value. If that one post doesn’t have the value, you’ll see nothing. What you want to be able to do is query for posts with the value rather than querying for posts and then testing for a value.
If you were to save the data via your own meta box as post meta data, you could do a simple meta query to load the posts that have those values, see WP_Query for more info.
$args = array(
'category_name' => 'main',
'meta_key' => 'top_articles',
'meta_value' => 'top_articles_left',
'posts_per_page' => -1
);
$query = new WP_Query( $args );