WooCommerce version 4.1 adds a new top-level menu item labelled Marketing which links to the new WooCommerce Marketing Hub. If you’d like to remove the Marketing Hub from your WordPress installation, the following filter can be applied.

 * Remove WooCommerce Marketing Hub.
function disable_features( $features ) {
	$marketing = array_search( 'marketing', $features );
	unset( $features[$marketing] );
	return $features;
add_filter( 'woocommerce_admin_features', 'disable_features' );

The filter above can be inserted using the Code Snippets plugin, a child theme or a custom plugin. If using the Code Snippets plugin, set the function to run in the site administration area.

Credit to Jason Conroy for the above function.