improve-security-wp-rest-routes.php

<?php

add_filter( 'rest_endpoints', 'disable_default_endpoints' );
function disable_default_endpoints( $endpoints ) {
        
    $allowed = ['/some/route/here'];

    foreach ( $endpoints as $maybe_endpoint => $object ) {    
        
        if ( ! in_array($maybe_endpoint, $allowed) ) {            
            unset( $endpoints[ $maybe_endpoint ] );
        }
    }

    return $endpoints;
}