Demo: https://salvatorenoschese.it/sitemap/

SitemapHTML.php

<?php
/*
Plugin Name: SimpleSitemapHTML
Description: Generates an HTML sitemap using a shortcode: [custom_sitemap]
Author: Salvatore Noschese
Author URI: https://salvatorenoschese.it
Version: 1.2
*/

// Deny direct access
defined('ABSPATH') || exit;

class SimpleSitemapHTML {

    public function __construct() {
        // Register the shortcode with parameters handling
        add_shortcode('custom_sitemap', [$this, 'generate_sitemap']);
    }

    /**
     * Generate the HTML sitemap content with optional parameters.
     *
     * @param array $atts Shortcode attributes.
     * @return string The generated sitemap HTML.
     */
    public function generate_sitemap($atts) {
        // Set default attributes
        $atts = shortcode_atts([
            'posts_num' => 100, // default: latest 100 posts
            'title_counter' => 'yes', // default: show counter
            'terms_num' => 45, // default: 45 terms
            'terms_counter' => true, // default: counter terms
            'yoast_sitemap' => 'yes', // default: show yoast xml
        ], $atts, 'custom_sitemap');

        if (!is_page()) {
            return "&#91;custom_sitemap]";
        }

        $output = '<div class="custom-sitemap-shortcode">';
        $output .= $this->render_pages_section($atts['title_counter']);
        $output .= $this->render_posts_section($atts['posts_num'], $atts['title_counter']);
        $output .= $this->render_taxonomy_section('Categories', 'category', $atts['title_counter'], $atts['terms_num'], $atts['terms_counter']);
        $output .= $this->render_taxonomy_section('Tags', 'post_tag', $atts['title_counter'], $atts['terms_num'], $atts['terms_counter']);

        if ($atts['yoast_sitemap'] === 'yes' && class_exists('WPSEO_Options') && WPSEO_Options::get('enable_xml_sitemap')) {
            $output .= '<hr />';
            $output .= '<p class="has-text-align-center">';
            $output .= '<a href="' . esc_url(WPSEO_Sitemaps_Router::get_base_url('sitemap_index.xml')) . '" class="wp-element-button">';
            $output .= esc_html__('See the XML sitemap.', 'wordpress-seo') . '</a></p>';
        }

        $output .= '</div>';
        return $output;
    }
    
    /* pages */
    private function render_pages_section($title_counter) {
        $output = '<hr />';
        $pages_title = esc_html__('Pages', 'default');
        if ($title_counter === 'yes') {
            $pages_title .= ' (' . esc_html(wp_count_posts('page')->publish - 1) . ')';
        }
        $output .= '<h2>' . $pages_title . '</h2>';
        $output .= '<ul>';

        $pages = wp_list_pages([
            'title_li' => '',
            'sort_column' => 'post_title',
            'sort_order' => 'ASC',
            'exclude' => get_the_ID(),
            'echo' => 0
        ]);
        
        $output .= $pages ? $pages : '<li>' . esc_html__('No pages found.', 'default') . '</li>';
        $output .= '</ul>';
        return $output;
    }

    /* posts */
    private function render_posts_section($posts_num, $title_counter) {
        $output = '<hr />';
        $posts_title = esc_html__('Posts', 'default');
        if ($title_counter === 'yes') {
            $total_posts = wp_count_posts('post')->publish;
            if ($posts_num != -1 && $posts_num < $total_posts) {
                $posts_title .= ' (' . sprintf(_x('%1$s of %2$s', 'paging'), esc_html($posts_num), esc_html($total_posts)) . ')';
            } else {
                $posts_title .= ' (' . esc_html($total_posts) . ')';
            }
        }
        $output .= '<h2>' . $posts_title . '</h2>';
        $output .= '<ul>';

        $posts = get_posts([
            'post_type' => 'post',
            'posts_per_page' => intval($posts_num),
            'orderby' => 'date',
            'order' => 'DESC',
        ]);

        if ($posts) {
            foreach ($posts as $post) {
                $output .= '<li>';
                $output .= '<a href="' . esc_url(get_permalink($post->ID)) . '" title="' . esc_attr(get_the_title($post->ID)) . '">';
                $output .= esc_html(get_the_title($post->ID)) . '</a> ';
                $output .= '<em>(' . esc_html(get_the_date(get_option('date_format'), $post->ID)) . ')</em>';
                $output .= '</li>';
            }
        } else {
            $output .= '<li>' . esc_html__('No posts found.', 'default') . '</li>';
        }

        $output .= '</ul>';
        return $output;
    }

    /* taxonomies (categories + tags) */
    private function render_taxonomy_section($title, $taxonomy, $title_counter, $terms_num, $terms_counter) {
        $output = '<hr />';
        $terms_title = esc_html__($title, 'default');
        if ($title_counter === 'yes') {
            $total_terms = wp_count_terms($taxonomy, ['hide_empty' => true]);
            if ($terms_num != 0 && $terms_num < $total_terms) {
                $terms_title .= ' (' . sprintf(_x('%1$s of %2$s', 'paging'), esc_html($terms_num), esc_html($total_terms)) . ')';
            } else {
                $terms_title .= ' (' . esc_html($total_terms) . ')';
            }
        }
        $output .= '<h2>' . $terms_title . '</h2>';
        $output .= '<ul>';

        if (!empty($total_terms)) {
            $output .= '<li>';
            $output .= wp_tag_cloud([
                'taxonomy' => $taxonomy,
                'smallest' => 8,
                'largest' => 22,
                'unit' => 'pt',
                'number' => intval($terms_num),
                'orderby' => 'name',
                'order' => 'ASC',
                'format' => 'flat',
                'show_count' => $terms_counter,
                'echo' => false
            ]);
            $output .= '</li>';
        } else {
            $output .= '<li>' . esc_html__('No terms found.', 'default') . '</li>';
        }

        $output .= '</ul>';
        return $output;
    }

}

// Initialize the plugin
new SimpleSitemapHTML();