Mu-plugins: Add a plugin to cache wp_count_posts() on the front-end.
WordPress.org themes often call wp_count_posts() to get the published post count, for example, the WordPress.org Plugins & Theme directories, and the WordPress.org Showcase.
This mu-plugin pre-sets the 'counts' cache group (which is a non-persistent cache group) on the front-end using wp_cache_get_last_changed() to invalidate it.
This removes often the final non-cached SQL query on these sites.