Is it possible to dynamically get queried term AND taxonomy?

In a taxonomy template, the queried object is an instance of WP_Term, one of whose fields will be the taxonomy the term comes from.

So, you can start your taxonomy.php as follows:

$queried_object = get_queried_object () ;
$args = array (
    'post_type' => 'inventory',
    'tax_query' => array (
        array (
            'taxonomy' => $queried_object->taxonomy,
            'field' => 'slug',
            'terms' => $queried_object->slug,
            ),
        ),
    ) ;
$query = new WP_Query ($args) ;