How To Disable Comment In Astra Theme without Plugin

Go to Apperance > Theme File Editor

then go to function.php and copy this

// Remove the default comments from Astra.
add_action(
	'init',
	function() {
		if ( class_exists( 'Astra_Loop' ) ) {
			remove_action( 'astra_template_parts_content', array( Astra_Loop::get_instance(), 'template_parts_comments' ), 15 );
		}
	},
	11
);

Code Credit: jan-koch

then paste at the end of this function.php file.