Accessibility Report for All Posts and Pages

add_action( 'admin_menu', function () {
    add_management_page( 'Accessibility Report', 'Accessibility Report', 'edit_others_posts', 'wpide-a11y-report', function () {
        $paged = max( 1, isset( $_GET['paged'] ) ? absint( $_GET['paged'] ) : 1 );
        $query = new WP_Query( array(
            'post_type'      => array( 'post', 'page' ),
            'post_status'    => 'publish',
            'posts_per_page' => 100,
            'paged'          => $paged,
            'orderby'        => 'modified',
        ) );

        echo '<div class="wrap"><h1>Accessibility Report</h1><table class="widefat striped"><thead><tr><th>Content</th><th>Problems</th></tr></thead><tbody>';
        $found = 0;
        foreach ( $query->posts as $post ) {
            $issues = array();
            if ( class_exists( 'WP_HTML_Tag_Processor' ) ) {
                $tags  = new WP_HTML_Tag_Processor( $post->post_content );
                $level = 1;
                while ( $tags->next_tag() ) {
                    $tag = $tags->get_tag();
                    if ( 'IMG' === $tag && null === $tags->get_attribute( 'alt' ) ) {
                        $issues['img'] = 'image without alt text';
                    } elseif ( 'IFRAME' === $tag && ! $tags->get_attribute( 'title' ) ) {
                        $issues['iframe'] = 'embed without a title';
                    } elseif ( preg_match( '/^H([1-6])$/', (string) $tag, $m ) ) {
                        if ( (int) $m[1] > $level + 1 ) {
                            $issues['heading'] = 'skipped heading level';
                        }
                        $level = (int) $m[1];
                    }
                }
            }
            if ( preg_match( '#<a\b[^>]*>\s*</a>#i', $post->post_content ) ) {
                $issues['link'] = 'empty link';
            }
            if ( ! $issues ) {
                continue;
            }
            $found++;
            printf( '<tr><td><a href="%s">%s</a> <span class="description">(%s)</span></td><td>%s</td></tr>', esc_url( get_edit_post_link( $post->ID ) ), esc_html( $post->post_title ? $post->post_title : '#' . $post->ID ), esc_html( $post->post_type ), esc_html( implode( ', ', $issues ) ) );
        }
        if ( ! $found ) {
            echo '<tr><td colspan="2">No problems found on this page of results.</td></tr>';
        }
        echo '</tbody></table>';
        if ( $query->max_num_pages > 1 ) {
            echo '<p>' . wp_kses_post( paginate_links( array( 'base' => add_query_arg( 'paged', '%#%' ), 'format' => '', 'current' => $paged, 'total' => $query->max_num_pages ) ) ) . '</p>';
        }
        echo '</div>';
    } );
} );