condition for only if is archive for default post type

In order to optimize my site for a bit more loading speed, I wanted to enqueue a couple of scripts only to the archives for default post type. A rough example is given below.

function my_theme_script_enqueues() {

        if (!is_admin()) {

            if ( is_archive()) {
                wp_register_script('isotope', get_template_directory_uri() . '/js/jquery.isotope.min.js', 'jquery');
                wp_enqueue_script('isotope');
            }
        }
    }

add_action (blah..blah..blah..blah)

I assumed something like (is_archive(‘post’)) would work, but it still loads on cpt-archive and tag archives and such ( does not load on pages though).

I cant use (is_archive()) as it again loads it to every other archive types eg. cpt-archives, tags etc which is pointless to me.

If I use if (!is_post_type_archive('cpt')) {...} then it obviously goes wild and loads it everywhere else, not scalable.

I know how to use if( is_post_type_archive('post')) {...}, but it is not giving me any result, which it should i guess as ‘post’ is a post-type right? When I search for a solution here I get mostly threads talking about custom post type archive. Please let me know what my alternative is?