Source

File: wp-includes/sitemaps/class-wp-sitemaps.php

public function sitemaps_enabled() {
		$is_enabled = (bool) get_option( 'blog_public' );

		/**
		 * Filters whether XML Sitemaps are enabled or not.
		 *
		 * When XML Sitemaps are disabled via this filter, rewrite rules are still
		 * in place to ensure a 404 is returned.
		 *
		 * @see WP_Sitemaps::register_rewrites()
		 *
		 * @since 5.5.0
		 *
		 * @param bool $is_enabled Whether XML Sitemaps are enabled or not. Defaults
		 * to true for public sites.
		 */
		return (bool) apply_filters( 'wp_sitemaps_enabled', $is_enabled );
	}